JP2007132969A - Electro-optical device and electronic apparatus - Google Patents

Abstract

An electro-optical device in which an electrostatic protection circuit is built in a limited area on a substrate without complicating the manufacturing process.
An MIM element 411 is sandwiched between an electrode 71a formed in the same layer as a lower electrode 71 constituting a storage capacitor 70, a power supply line 93 formed in the same layer as a capacitor electrode 300, and the electrode 71a and the power supply line 93. The insulating film 75a is formed in the same layer as the dielectric film 75. Each of the electrode 71a and the power supply line 93 is formed by the same process using the same material as the lower electrode 71 and the capacitor electrode 300. Therefore, since the electrode 71a, the insulating film 75a, and the power supply line 93 can be formed using the process of forming the storage capacitor 70, the manufacturing process of the liquid crystal device 1 is complicated without greatly changing the design of the liquid crystal device 1. The MIM element 411 is formed without doing so.
[Selection] Figure 14

Description

  The present invention relates to a technical field of electro-optical devices such as liquid crystal devices and electronic devices such as liquid crystal projectors.

  In a liquid crystal device which is an example of this type of electro-optical device, an electro-optical material such as liquid crystal is sandwiched between a pair of substrates. A plurality of pixel electrodes are provided on an element substrate which is one of these substrates. In addition, a counter substrate which is the other of these substrates is provided with a counter electrode facing the plurality of pixel electrodes. Further, the element substrate is provided with peripheral circuits such as a data line driving circuit and a scanning line driving circuit for driving the pixel electrode, and a plurality of lead wirings are routed from the plurality of external circuit connection terminals to the peripheral circuit. Has been. As a factor of such deterioration or destruction of the peripheral circuit, at the time of mounting or assembly in the manufacturing process of the peripheral circuit or the electro-optical device including the peripheral circuit, at the time of shipment or storage, and further at the time of using the product after shipment, In addition to the addition of temperature and humidity, mechanical impact, etc., breakdown due to stress of electrostatic discharge, which is a problem particularly during assembly or transportation of the electro-optical device, or electrostatic breakdown during operation of the electro-optical device can be mentioned. Static electricity is generated around the peripheral circuit or the electro-optical device at the time of assembly or the like, and when this is applied to the wiring connected to the peripheral circuit, the peripheral circuit is deteriorated or destroyed. As a result, the production yield decreases and the apparatus fails after shipment.

  In order to prevent such deterioration or destruction of the drive circuit due to static electricity, the electrostatic protection diode disclosed in Patent Document 1 may be used. An electrostatic protection circuit formed by providing such an electrostatic protection diode in a signal path related to signal input / output of a peripheral circuit is, for example, various signals such as a clock signal, an inverted clock signal, and a start pulse from the outside of the peripheral circuit. Is provided as an input protection circuit for an input terminal to which is input.

JP 63-306663 A

  However, since the electrostatic protection diode disclosed in Patent Document 1 has a P-type impurity region and an N-type diffusion region formed in predetermined regions on a semiconductor substrate, a process for forming the electrostatic protection diode Is complicated. In addition, it is difficult to secure a region for forming this in a limited region on the substrate. In particular, in the case of a small electro-optical device or an electro-optical device in which the ratio of the image display area to the substrate is large, there is a problem that it is very difficult to secure such an area. For example, a semiconductor element such as a MOS TFT has a semiconductor layer in which a channel region, a source region, and a drain region are formed in the same layer on a substrate. Accordingly, it is necessary to form a semiconductor layer having a sufficient size for forming each of these regions in a limited region on the substrate, which is an obstacle in reducing the size of the electro-optical device and increasing the ratio of the image display region. It was. In addition, in order to electrically connect the source region and the drain region formed in the semiconductor layer to the outside of the element, for example, a contact hole may be formed in an insulating film formed on the semiconductor layer. There is a problem that the manufacturing process of the apparatus becomes complicated. These problems become more prominent as the electro-optical device becomes smaller and the ratio of the image display area to the substrate increases. Therefore, it is practically difficult to form an electrostatic protection circuit for preventing voltage breakdown of peripheral circuits due to static electricity while solving these problems.

  Therefore, the present invention has been made in view of the above-described problems. For example, an electro-optical device in which an electrostatic protection circuit is built in a limited area on a substrate without complicating the manufacturing process, and It is an object to provide an electronic apparatus including such an electro-optical device.

In order to solve the above problems, an electro-optical device according to a first aspect of the present invention includes a substrate, a plurality of pixel portions formed in a pixel region on the substrate, and a peripheral region positioned around the pixel region. A peripheral circuit portion for controlling the pixel portion, and a signal wiring for electrically connecting the peripheral circuit portion and an input terminal for inputting an input signal to the peripheral circuit portion,
A power supply line for supplying a power supply potential to the peripheral circuit portion, a first metal film formed on the substrate and electrically connected to the signal wiring, and the first metal film when viewed in plan view The second metal film is formed in a layer different from the first metal film and is electrically connected to the power line, and the insulating film interposed between the first metal film and the second metal film. And an electrostatic protection circuit made of the formed MIM element.

  According to the electro-optical device according to the first aspect of the present invention, the internal circuit unit is formed on the substrate, and controls driving of the pixel unit and, for example, the pixel unit of the data line driving circuit and the scanning line driving circuit. And a peripheral circuit section including a drive circuit and the like. The internal circuit unit is electrically connected to a signal wiring for inputting an input signal to the internal circuit unit, and the peripheral circuit unit is electrically connected to a power supply line that supplies power to the peripheral circuit unit. The input signals are, for example, various signals such as a clock signal supplied from the outside of the internal circuit unit, an inverted clock signal, a start pulse, and a counter electrode potential signal supplied to the counter electrode included in the pixel unit. The signal is supplied to the internal circuit section through a signal wiring electrically connected to the terminal and the input terminal.

  In the electro-optical device according to the first aspect of the present invention, the MIM element allows the static electricity applied to the signal wiring to escape to the power supply line and reduces the destruction of the internal circuit portion due to the static electricity. More specifically, the MIM element includes a first metal film formed on the substrate and electrically connected to the signal wiring, and the first metal film so as to overlap the first metal film in plan view. A second metal film formed in a different layer and electrically connected to the power line, and an insulating film interposed between the first metal film and the second metal film, a metal film (Metal), It has a three-layer structure consisting of an insulating film (Insulator) and a metal film (Metal). Such a three-layer structure constitutes a capacity of a capacitor or the like as it is, but, for example, based on a current-voltage characteristic defined by the pool-Frankel effect, a potential difference generated between both metal films, and A current path through which a current flows between the metal films sandwiching the insulating film according to the direction of the potential gradient can be provided.

  Here, the Pool-Frankel effect is an effect in which current flows in one direction according to the potential difference and the direction of the potential gradient when the potential difference between the metal films becomes a certain level or more. More specifically, for example, when the potential of the first metal film is greater than or equal to a certain level compared to the potential of the second metal film, a current flows from the first metal film to the second metal film through the insulating film. Flowing. Therefore, when a high voltage due to static electricity is applied to the signal wiring electrically connected to the first metal film, the static electricity is released to the power supply line via the MIM element. Thereby, the static electricity applied to an internal circuit part via an input terminal can be suppressed, and it can reduce that an internal circuit part is electrostatically destroyed. Note that the MIM element may be formed in front of the internal circuit portion as viewed from the input terminal in accordance with the layout of the input terminal, signal wiring, and internal circuit portion.

  Here, the current flowing between the first metal film and the second metal film, which are both electrodes of the MIM element, is symmetric according to the potential difference generated between the two metal films. That is, the MIM element has a symmetric current-voltage characteristic according to the potential difference generated between the electrodes. Here, “the current-voltage characteristics are symmetric” means that a current flows in the forward direction and a potential difference is generated in the reverse direction only when a potential difference is generated in the forward direction as in a normal diode element. An asymmetric current-voltage characteristic in which no current flows in the circuit means an opposite characteristic. More specifically, when the potential of the other electrode is set higher than the potential of one electrode of both electrodes of the MIM element, and the potential difference between these electrodes becomes a certain voltage or more, the other electrode Means current-voltage characteristics in which current flows from one electrode to the other electrode and current flows from one electrode to the other when the potential relationship between one electrode and the other electrode is reversed. To do. The MIM element has a threshold voltage on the high potential side and the low potential side defined by the same potential on each of the positive side and the negative side with respect to one potential of the metal film. Therefore, in the MIM element, a current flows according to the potential difference when the potential difference between the first metal film and the second metal film becomes equal to or higher than the threshold voltage.

  The threshold voltage of the MIM element is set to be larger than the potential of the input signal supplied to the signal wiring. Therefore, normally, the input signal supplied to the signal wiring via the input terminal is supplied to the internal circuit unit without being released to the power supply line. When a voltage exceeding the threshold voltage of the MIM element is applied, the MIM element provides a current path through which current caused by this voltage is released.

  As a result, the electro-optical device according to the first aspect of the present invention can supply an input signal to the internal circuit section through the signal wiring when performing a normal operation, and an abnormality caused by static electricity or the like. Only when a signal voltage is applied to the signal wiring, the current generated due to the abnormal voltage can be released to the power supply line through the MIM element. The current-voltage characteristic based on the pool-Frankel effect of the MIM element will be described in more detail in an embodiment described later. Further, in this specification, the “metal film” is not limited to a case of being formed of a pure metal material, and is formed of a material capable of forming an MIM element that exhibits a pool-Frankel effect by sandwiching an insulating film. Any film may be used.

  In the electro-optical device according to the first aspect of the present invention, the first metal film, the insulating film, and the second metal film forming the MIM element are formed in different layers and overlapped in a plane. Therefore, the MIM element can be formed in a narrow region on the substrate in plan view. More specifically, the MIM element can be reduced in size in plan view compared to a semiconductor element such as MOSTFT in which the impurity region and the diffusion region are spread in the semiconductor layer, and is formed in a narrow region on the substrate. . Therefore, the MIM element is used for a layout of a peripheral circuit unit included in an internal circuit unit in, for example, a small electro-optical device or an electro-optical device in which an image display region corresponding to a pixel region occupies most of the region on the substrate. It is formed without any restrictions. In addition, according to the electro-optical device according to the first aspect of the present invention, there is no need to electrically connect the semiconductor layer and the electrode via the contact hole unlike the semiconductor element such as MOSTFT. Without complicating the device manufacturing process, it is possible to reduce the possibility of internal circuit portions being destroyed by static electricity.

  In one aspect of the electro-optical device according to the first aspect of the present invention, the pixel unit includes a storage capacitor in which a lower electrode, a dielectric film, and an upper electrode are sequentially stacked on the substrate. Each of the first metal film and the second metal film is formed in the same layer as the metal film constituting each of the lower electrode and the upper electrode, and the insulating film is the same layer as the dielectric film. It may be formed.

  According to this aspect, the first metal film, the insulating film, and the second metal film are formed in the same layer as the layer on which the lower electrode, the dielectric film, and the upper electrode that form the storage capacitor are formed. In addition, the first metal film, the insulating film, and the second metal film included in the MIM element are formed by the same film forming process using the materials constituting the upper electrode, the dielectric film, and the lower electrode included in the storage capacitor. Therefore, the MIM element can be formed without significantly changing the design and manufacturing process of the electro-optical device.

  In another aspect of the electro-optical device according to the first aspect of the present invention, each of the first metal film and the second metal film is a part of a metal film constituting each of the signal wiring and the power supply line. It may be.

  According to this aspect, since the MIM element can be formed by a part of the signal wiring and the power supply line, the MIM element can be formed without complicating the layout of the wiring and the like formed on the substrate. The first metal film and the second metal film may share part of the signal wiring and the power supply line as they are as a part of the MIM element. It may be formed by a protruding portion.

  In another aspect of the electro-optical device according to the first aspect of the present invention, the power line is a low-potential power line that supplies a low-potential power having a potential lower than the potential of the signal wiring to the peripheral circuit unit. The second metal film may be electrically connected to the low potential power supply line.

  In this aspect, the low-potential power supply line is a power supply line for supplying a low-potential power supply having a lower potential than the signal wiring to the TFT source included in the peripheral circuit portion, for example. When the threshold voltage on the high potential side among the threshold voltages of the MIM element is set slightly higher than the potential of the input signal supplied to the signal wiring with reference to the potential of the low potential power supply line, for example, the MIM element Provided is a current path through which a current flows from the first metal film to the second metal film when static electricity having a voltage higher than the threshold voltage on the high potential side is applied to the signal wiring. Further, when static electricity having a potential lower than the potential of the low potential signal line is applied to the signal wiring, if the electrostatic potential is lower than the threshold voltage on the low potential side of the threshold voltage of the MIM element, the signal wiring The MIM element provides a current path through which a current flows from the second metal film to the first metal film so as to cancel applied static electricity or the like. As described above, the MIM element is changed from the first metal film to the second metal film or from the second metal film to the second metal film according to the combination of the electrostatic potential applied to the signal wiring, the potential of the low potential power supply line, and the threshold voltage. It is possible to flow a current to one metal film bidirectionally, and the voltage breakdown of the internal circuit portion due to static electricity applied to the signal wiring is reduced.

  In another aspect of the electro-optical device according to the first aspect of the present invention, the power supply line is a high potential power supply line that supplies a high potential power supply having a potential higher than the potential of the signal wiring to the peripheral circuit portion. The second metal film may be electrically connected to the high potential power line.

  In this aspect, the high-potential power line is a power line for supplying a high-potential power having a higher potential than the signal wiring to the drain of the TFT included in the peripheral circuit portion, for example. When the threshold voltage on the low potential side with respect to the potential of the high potential power source among the threshold voltages of the MIM element is set to a potential slightly lower than the potential of the input signal supplied to the signal wiring, the MIM element Provides a current path through which current flows from the second metal film to the first metal film so as to release static electricity having a potential lower than the threshold voltage on the low potential side. Thereby, even when static electricity having a lower potential than the input signal input to the signal wiring is applied to the signal wiring, the MIM element can reduce electrostatic breakdown of the internal circuit portion due to the static electricity.

  In order to solve the above problems, an electro-optical device according to a second aspect of the present invention includes a substrate, a plurality of pixel portions formed in the pixel region on the substrate, and a peripheral region located around the pixel region. A peripheral circuit unit for controlling the pixel unit, a signal wiring for electrically connecting the peripheral circuit unit and an input terminal for inputting an input signal to the peripheral circuit unit, and A high potential power supply line for supplying a power supply potential higher than a predetermined potential to the peripheral circuit portion, a low potential power supply line for supplying a power supply potential lower than the predetermined potential, and the signal wiring on the substrate. A part of the first metal film connected to the first metal film and a layer different from the first metal film so as to overlap the part in plan view and electrically connected to the high-potential power line. Second metal film and the part And the first MIM element formed by the first insulating film interposed between the second metal films, the other part of the first metal film, and the other part so as to overlap with the other part in plan view. A second MIM element formed by a third metal film formed and electrically connected to the low-potential power line, and a second insulating film interposed between the other part and the third metal film; And an electrostatic protection circuit.

  According to the electro-optical device according to the second aspect of the present invention, as in the electro-optical device according to the first aspect of the present invention, the internal circuit portion is formed on the substrate, and the pixel portion and, for example, the data And a peripheral circuit portion including a drive circuit for controlling driving of the pixel portion of the line driver circuit and the scan line driver circuit. The internal circuit unit is electrically connected to a signal wiring for inputting an input signal to the internal circuit unit, and the peripheral circuit unit is electrically connected to a power supply line that supplies power to the peripheral circuit unit.

  In the electro-optical device according to the second aspect of the present invention, the first MIM element and the second MIM element allow static electricity applied to the signal wiring to escape to at least one of the high-potential power line and the low-potential power line, and the internal circuit section Reduce damage from static electricity. More specifically, the first MIM element includes the first metal so as to overlap a part of the first metal film electrically connected to the signal wiring on the substrate and a part of the first metal film in plan view. Formed by a second metal film that is formed in a different layer from the film and is electrically connected to the high-potential power line, and a first insulating film interposed between a part of the first metal film and the second metal film The second MIM element is formed in a separate layer so as to overlap the other part of the first metal film and the other part of the first metal film in plan view, and is electrically connected to the low-potential power line. And a second insulating film interposed between the third metal film and the other part of the first metal film and the third metal film.

  Each of the first MIM element and the second MIM element has a three-layer structure including a metal film (Metal), an insulating film (Insulator), and a metal film (Metal). Such a three-layer structure constitutes a capacity of a capacitor or the like as it is, but based on the current-voltage characteristics defined by the Pool-Frankel effect as in the first invention of the present invention, The first insulating film and the first metal film according to the potential difference between the first metal film and the second metal film and the direction of the potential gradient and the potential difference generated between the third metal film and the second metal film and the direction of the potential gradient. It is possible to provide a current path through which a current flows between the metal films sandwiching the two insulating films.

  Here, the Pool-Frankel effect is defined in the same manner as the electro-optical device according to the first invention of the present invention. Therefore, detailed description is omitted here, but the electric power according to the second invention of the present invention is omitted. Similarly to the electro-optical device described above, the optical device can suppress static electricity applied to the internal circuit portion via the input terminal, and can reduce the electrostatic breakdown of the internal circuit portion. Note that the MIM element may be formed in front of the internal circuit portion as viewed from the input terminal in accordance with the layout of the input terminal, signal wiring, and internal circuit portion.

  In the electro-optical device according to the second aspect of the present invention, for example, the threshold voltage on the low potential side of the threshold voltage when the first MIM element provides the current path is slightly lower than the potential of the input signal supplied to the signal wiring. Is set to a low potential. As a result, the MIM element provides a current path through which current flows from the second metal film to the first metal film when static electricity having a potential lower than the threshold on the low potential side is applied to the signal wiring. Further, the threshold on the high potential side among the threshold voltages when the second MIM element provides the current path is set to a potential slightly higher than the potential of the input signal supplied to the signal wiring. As a result, the second MIM element provides a current path through which a current flows from the second metal film to the third metal film when static electricity having a potential higher than the threshold on the high potential side is applied to the signal wiring.

  Therefore, the first metal film that electrically connects the first MIM element and the second MIM element is electrically connected to the signal line, and the second metal film and the third metal film are respectively connected to the high potential power line and the low potential power source. By electrically connecting to each of the lines, even when static electricity having a slightly higher potential and a slightly lower potential than the potential of the input signal supplied to the signal wiring is applied to the signal wiring, A current that tends to flow to the peripheral circuit portion due to each potential can be released to at least one of the high potential power line and the low potential power line via the first MIM element and the second MIM element.

  Here, a current flows through each of the first MIM element and the second MIM element when the potential difference between one electrode and the other electrode becomes equal to or higher than the threshold voltage. That is, each of the first MIM element and the second MIM element has a symmetric current-voltage characteristic.

  Therefore, in order to prevent current from flowing from the high potential power supply line and the low potential power supply line to the signal wiring during normal operation of the electro-optical device, for example, the threshold voltage on the high potential side of the first MIM element is set to a high level. It is necessary to set it higher than the potential of the potential power supply line and set the threshold voltage on the low potential side of the second MIM element to be lower than the potential of the low potential power supply line. Under such a premise, the first MIM element and the second MIM element, which have symmetrical current-voltage characteristics, increase all currents caused by static electricity having a potential higher than that of the input signal and static electricity having a low potential. It is possible to escape to at least one of the potential power supply line and the low potential power supply line.

  As described above, according to the electro-optical device according to the second aspect of the present invention, the electric signal having the potential exceeding the upper limit and the lower limit of the potential of the input signal input to the signal wiring flows when applied. The current can be released to at least one of the high potential power line and the low potential power line, and the current flows from the high potential power line and the low potential power line to the signal wiring during the operation of the normal electro-optical device. Can be prevented. Therefore, according to the electro-optical device according to the second aspect of the present invention, the normal operation of the electro-optical device is maintained, and the internal circuit portion is prevented from being destroyed by voltage when static electricity is applied to the signal wiring. it can. In addition, similarly to the electro-optical device according to the first aspect of the present invention, an electro-optical device excellent in reliability can be provided by a simple manufacturing process without complicating the manufacturing process of the electro-optical device.

  In one aspect of the electro-optical device according to the second aspect of the present invention, the pixel unit includes a storage capacitor in which a lower electrode, a dielectric film, and an upper electrode are sequentially stacked on the substrate, The first metal film, the second metal film, and the third metal film are formed in the same layer as a metal film that constitutes each of the lower electrode and the upper electrode, and the first insulating film and The second insulating film may be formed in the same layer as the dielectric film.

  According to this aspect, the first metal film, the second metal film, the third metal film, and the first insulation are formed in the same layer as each of the lower electrode, the dielectric film, and the upper electrode that form the storage capacitor. A film and a second insulating film are formed. In addition, the first metal film, the second metal film, the third metal film, the first insulating film, and the second insulating film use materials that constitute the upper electrode, the dielectric film, and the lower electrode included in the storage capacitor. Therefore, the first MIM element and the second MIM element can be formed using the same process as the process of forming the storage capacitor without greatly changing the design of the electro-optical device.

  In another aspect of the electro-optical device according to the second aspect of the present invention, the second metal film and the third metal film may be formed by partially removing the metal film.

  According to this aspect, for example, the metal film is formed in the same layer as the upper electrode or the lower electrode included in the storage capacitor by the same process, and then separated from each other by partially removing the metal film by an etching process. A second metal film and a third metal film can be formed. According to this aspect, the first MIM element and the second MIM element can be formed in a narrow region on the substrate without complicating the manufacturing process.

  In order to solve the above problems, an electronic apparatus according to the present invention includes the above-described electro-optical device of the present invention.

  According to the electronic apparatus according to the present invention, since the electro-optical device according to the present invention described above is included, problems due to disturbances such as static electricity are unlikely to occur. Projection display device, mobile phone, electronic notebook, word processor, 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. In addition, as an electronic apparatus according to the present invention, for example, an electrophoretic device such as electronic paper can be realized.

  Such an operation and other advantages of the present invention will become apparent from the embodiments described below.

  Hereinafter, embodiments of an electro-optical device according to first and second inventions of the present invention and an electronic apparatus including such an electro-optical device will be described with reference to the drawings.

(First embodiment)
First, an embodiment of an electro-optical device according to the first invention of the present invention will be described with reference to FIGS. In this embodiment, the electro-optical device according to the first invention is applied to a liquid crystal device.

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

  1 and 2, in the liquid crystal device 1 according to the present embodiment, a TFT array substrate 10 and a counter substrate 20 are disposed to face each other. 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 positioned around the image display region 10a. Are bonded to each other. The image display area 10a corresponds to the “pixel area” of the present invention.

  In FIG. 1, a light-shielding frame light-shielding film 53 that defines the frame area of the image display 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. In the peripheral region, the data line driving circuit 101 and the external circuit connection terminal 102 which is an example of the “input terminal” of the present invention are disposed in the TFT array substrate 10 in a region located outside the sealing region where the sealing material 52 is disposed. It is provided along one side. The sampling circuit 7 is provided so as to be covered with the frame light shielding film 53 on the inner side of the seal region along the one side. Further, the scanning line driving circuit 104 is provided so as to be covered with the frame light-shielding film 53 inside the seal region along two sides adjacent to the one side. On the TFT array substrate 10, vertical conduction terminals 106 for connecting the two substrates with the vertical conduction material 107 are arranged in regions facing the four corner portions of the counter substrate 20. Thus, electrical conduction can be established between the TFT array substrate 10 and the counter substrate 20.

  Formed on the TFT array substrate 10 are a data line driving circuit 101 and a scanning line driving circuit 104 constituting an example of the “peripheral circuit portion” of the present invention, and a lead wiring 90 including an example of the “signal wiring” of the present invention. Has been. The lead wiring 90 electrically connects the external connection terminal 102 to the data line driving circuit 101, the scanning line driving circuit 104, the vertical conduction terminal 106, and the like.

  In FIG. 2, on the TFT array substrate 10, a laminated structure in which wiring such as a pixel switching TFT (Thin Film Transistor) as a driving element, a scanning line, and a data line is formed. In the image display area 10a, a pixel electrode 9a is provided in an upper layer of wiring such as a pixel switching TFT, a scanning line, and a data line. 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. A counter electrode 21 made of a transparent material such as ITO is formed on the light shielding film 23 so as to face the plurality of pixel electrodes 9a.

  On the TFT array substrate 10, in addition to the data line driving circuit 101 and the scanning line driving circuit 104, an inspection circuit for inspecting quality, defects, etc. of the liquid crystal device during manufacturing or at the time of shipment, and an inspection pattern Etc. may be formed.

  Next, the main configuration of the liquid crystal device 1 will be described with reference to FIG. FIG. 3 is a diagram illustrating a configuration of a main part of the liquid crystal device 1 according to the present embodiment.

  3, the liquid crystal device 1 includes a pixel electrode 9a, a scanning line 2, a data line 3, a scanning line driving circuit 104, a data line driving circuit 101, a sampling circuit 7, an electrostatic protection circuit 410, and an “input terminal” of the present invention. The external circuit connection terminal 102 and the lead wiring 90 which are an example are provided.

  In the liquid crystal device 1, for example, a TFT array substrate 10 made of, for example, a quartz substrate, a glass substrate, or a silicon substrate, and a counter substrate 20 (not shown here) are arranged to face each other with a liquid crystal layer interposed therebetween, and are partitioned in an image display region 10 a. The voltage applied to the pixel electrode 9a is controlled to modulate the electric field applied to the liquid crystal layer for each pixel. Thereby, the amount of transmitted light between the two substrates is controlled, and the image is displayed in gradation. The liquid crystal device 1 employs a TFT active matrix driving method, and a pixel display region 10a in the TFT array substrate 10 includes a plurality of pixel electrodes 9a arranged in a matrix, a plurality of scanning lines 2 arranged in an intersecting manner, and A data line 3 is formed, and a pixel portion corresponding to the pixel is constructed. Such a pixel portion constitutes an example of the “internal circuit portion” of the present invention together with the data line driving circuit 101, the scanning line driving circuit 104, and the sampling circuit 7 that constitute an example of the “peripheral circuit portion” of the present invention. Although not shown here, between each pixel electrode 9a and the data line 3, a TFT or a pixel electrode whose conduction or non-conduction is controlled according to a scanning signal supplied via the scanning line 2 respectively. A storage capacitor for maintaining the voltage applied to 9a is formed. In addition, a drive circuit such as the data line drive circuit 101 is formed in the peripheral area of the image display area 10a.

  The routing wiring 90 includes a power supply line 93 and a signal wiring 92, and is routed to a peripheral area located around the image display area 10a.

  The power supply line 93 includes a high potential power supply line 93 d for supplying the first power supply signal VDDY to the scanning line driving circuit 104 and a low potential power supply line 93 s for supplying the second power supply signal VSSY to the scanning line driving circuit 104. It is out. The high-potential power supply line 93d supplies power to the scanning line driving circuit 104 with a potential higher than various input signals supplied from the external circuit connection terminal 102, which will be described later, via the signal wiring 92. The low-potential power line 93s supplies the scanning line drive circuit 104 with a ground potential lower than various input signals supplied from the external circuit connection terminal 102, which will be described later, via the signal wiring 92. Similar to the scanning line driving circuit 104, the first power supply signals VDDX 1, VDDX 2, VDDX 3 and the second power supply signals VSSX 1, VSSX 2, VSSX 3 are supplied to the data line driving circuit 101 via the power supply line 93. .

  The signal wiring 92 includes an image signal VID input from a plurality of external circuit connection terminals 102 provided at the end of the substrate 10, precharge selection signals NRG, enable signals EMB1 to EMB4, start pulses DX and DY, and a clock signal CLX. And input signals such as CLY, inverted clock signal CLXB, counter electrode potential signal LCCOM, and the like are supplied to the pixel portion including the data line driving circuit 101, the scanning line driving circuit 104, and the pixel electrode 9a.

  The electrostatic protection circuit 410 is electrically connected to the power supply line 93 and the signal wiring 92, and in the circuit configuration on the substrate 10, the internal circuit unit including the data line driving circuit 101 and the like as viewed from the external circuit connection terminal 102. Connected to the front. The electrostatic protection circuit 410 provides a current path for releasing the static electricity applied to the external circuit connection terminal 102 by the MIM element, which will be described in detail later, to the power supply line 93, and the internal circuit unit including the data line driving circuit 101 and the like is static. Reduces electrical breakdown.

  The data line driving circuit 101 includes a shift register 51, a logic circuit 52, and a phase difference correction circuit 108.

  The shift register 51 receives the transfer signal Pi (i = i =) from each stage based on the X-side clock signal CLX (and its inverted signal CLX ′) and the shift register start signal DX inputted in the data line driving circuit 101. 1,..., N) are sequentially output. During the operation of the liquid crystal device 1, the shift register 51 is supplied with the power supply VDDX 1 and the power supply VSSX 1 having a lower potential than the power supply, and the transistors constituting the shift register 51 are driven. More specifically, the first power supply signal VDDX1 is a power supply that is supplied to the drain of the transistor that constitutes the shift register 51, and the second power supply signal VSSX1 is supplied to the source of the transistor that constitutes the shift register 51. Power supply. Note that power supplies VSSX and VSSY described later are power supplies having a lower potential than the power supplies VDDX and VDDY. The logic circuit 52 includes pulse width limiting means, which shapes the transfer signal Pi sequentially output from the shift register 51 based on the enable signals ENB1 to ENB4, and finally determines the sampling circuit drive signal Si based thereon. It has a function to output. The phase difference correction circuit 108 is disposed in the middle of a signal line that supplies each of the clock signal CLX and the inverted clock signal CLXB, and between the clock signal CLX (in other words, the normal clock signal) and the inverted clock signal CLXB. Adjust the timing appropriately.

  Next, the operation of the liquid crystal device 1 of the present embodiment configured as described above will be described with reference to FIG.

  During the operation of the liquid crystal device 1, the data line driving circuit 101 is operated from the external circuit connected to the external circuit connection terminal 102 via the FPC or the like via the external circuit connection terminal 102 and the lead wiring 90. Various signals such as a clock signal CLX and an image signal VID, and power supplies such as the first power supply signals VDDX1, VDDX2, and VDDX3 and the second power supply signals VSSX1, VSSSX2, and VSSSX3 are supplied to the data line driving circuit 101. In parallel with this, a signal such as a clock signal for operating the scanning line driving circuit 104 from the external circuit via the external circuit connection terminal 102 and the lead wiring 90, the first power supply signal VDDY and the second power signal Power such as a power supply signal VSSY is supplied to the scanning line driver circuit 104. At this time, the image signal VID is supplied to the sampling circuit 7 through a predetermined image signal line included in the signal wiring 92. On the other hand, the counter electrode potential LCCOM is supplied to the counter electrode 21 by a predetermined wiring electrically connected to the counter electrode 21 (see FIG. 2) through the vertical conductive terminal 106 and the vertical conductive material 107 in the signal wiring 92. Is done. As a result, the image signal VID is supplied to the pixel portion by the data line driving circuit 101 via the data line 3, and the scanning signal is supplied to the pixel portion by the scanning line driving circuit 104 via the scanning line 2. Active matrix driving is performed by driving the liquid crystal layer 50 sandwiched between 9a and the counter electrode 21 in each pixel portion.

  Particularly in the present embodiment, since the electrostatic protection circuit 410 is electrically connected between the internal circuit portions including the external circuit connection terminal 102 and the data line driving circuit 101, the liquid crystal device 1 is completed or delivered. Alternatively, static electricity applied to the external circuit connection terminal 102 during operation of the liquid crystal device 1 is released to the power supply line 93 by the electrostatic protection circuit 410. Accordingly, when a DC voltage is applied between the pixel electrode 9a and the counter electrode 21 due to static electricity applied to the external circuit connection terminal 102, the liquid crystal layer 50 (see FIG. 2) sandwiched between both electrodes is burned. It is possible to effectively avoid the situation and the situation where an element such as a TFT constituting the internal circuit unit including the data line driving circuit 101 is electrostatically destroyed. In addition, the electrostatic protection circuit 410 allows the static electricity to escape to the power supply line 93 by the MIM element formed using a multilayer structure formed on the substrate 10 as will be described in detail later. Even if it is formed on the substrate 10, the possibility of electrostatic breakdown of the internal circuit portion including the data line driving circuit and the like can be remarkably reduced without greatly changing the design of the liquid crystal device 1. is there. If the electrostatic protection circuit 410 is formed in this manner, it is extremely advantageous in practice because it does not cause an increase in the size of the substrate or the entire apparatus, and does not cause an apparatus failure due to electrostatic breakdown.

<Image display area configuration>
Next, the configuration of the pixel portion of the liquid crystal device 1 will be described with reference to FIGS. FIG. 4 is an equivalent circuit diagram of various elements and wirings in the pixel portion formed in the image display area of the liquid crystal device. 5 to 7 are plan views showing a partial configuration related to the pixel portion on the TFT array substrate. 5 and 6 correspond to a lower layer portion (FIG. 5) and an upper layer portion (FIG. 6), respectively, of a laminated structure described later. FIG. 7 is an enlarged plan view of the laminated structure, in which FIGS. 5 and 6 are superimposed. FIG. 8 is a cross-sectional view taken along line AA ′ when FIGS. 5 and 6 are overlapped. In FIG. 8, the scale of each layer / member is different for each layer / member so that each layer / member can be recognized on the drawing.

<Principle configuration of pixel unit>
In FIG. 4, each of a plurality of pixels formed in a matrix that forms the image display area of the liquid crystal device 1 is formed with a pixel electrode 9 a and a TFT 30 for controlling the switching of the pixel electrode 9 a. 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 to be 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. May be.

  The scanning line 11a is electrically connected to the gate of the TFT 30, and the scanning signals G1, G2,..., Gm are applied to the scanning line 11a in a pulse-sequential manner in this order at a predetermined timing. It is configured. The pixel electrode 9a is electrically connected to the drain of the TFT 30, and the image signal S1, S2,... Supplied from the data line 6a is closed by closing the switch of the TFT 30 serving as a switching element for a certain period. Sn is written at a predetermined timing.

  A predetermined level of image signals S1, S2,..., Sn written in the liquid crystal as an example of the electro-optical material via the pixel electrode 9a is held for a certain period with the counter electrode formed on the counter substrate. The The liquid crystal 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 light transmittance 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 in parallel with the liquid crystal capacitor formed between the pixel electrode 9a and the counter electrode. One electrode of the storage capacitor 70 is connected to the drain of the TFT 30 in parallel with the pixel electrode 9a, and the other electrode is connected to the capacitor wiring 400 with a fixed potential so as to have a constant potential.

<Specific configuration of pixel portion>
Next, a specific configuration of the pixel portion that realizes the above-described operation will be described with reference to FIGS.

  5 to 8, each circuit element of the pixel portion described above is structured on the TFT array substrate 10 as a patterned conductive film. Each circuit element includes, in order from the bottom, a first layer including the scanning line 11a, a second layer including the TFT 30 and the like, a third layer including the data line 6a and the like, a fourth layer including the storage capacitor 70 and the like, the pixel electrode 9a and the like. It consists of the 5th layer containing. Further, the base insulating film 12 is provided between the first layer and the second layer, the first interlayer insulating film 41 is provided between the second layer and the third layer, the second interlayer insulating film 42 is provided between the third layer and the fourth layer, and the fourth layer. A third interlayer insulating film 43 is provided between the layer and the fifth layer, respectively, to prevent a short circuit between the aforementioned elements. Of these, the first to third layers are shown in FIG. 5 as lower layer portions, and the fourth to fifth layers are shown in FIG. 6 as upper layer portions.

(Structure of the first layer-scanning lines, etc.)
The first layer is composed of scanning lines 11a. The scanning line 11a is patterned into a shape including a main line portion extending along the X direction in FIG. 5 and a protruding portion extending in the Y direction in FIG. 4 where the data line 6a extends. The scanning line 11a is made of, for example, conductive polysilicon, and at least one of refractory metals such as titanium (Ti), chromium (Cr), tungsten (W), tantalum (Ta), and molybdenum (Mo). It is possible to form a single metal containing one metal, an alloy, metal silicide, polysilicide, or a laminate thereof. In the present embodiment, in particular, the scanning line 11a is arranged on the lower layer side of the TFT 30 so as to include a region facing the channel region 1a, and is made of a conductive film. For this reason, when a double-plate projector is constructed using a back surface reflection on the TFT array substrate 10 or a liquid crystal device as a light valve, light emitted from another liquid crystal device and penetrating a synthetic optical system such as a prism is used. As for return light, the channel region 1a can be shielded from the lower layer side by the scanning line 11a.

(Second layer configuration-TFT, etc.)
The second layer is composed of the TFT 30. The TFT 30 has an LDD (Lightly Doped Drain) structure, for example, and includes a gate electrode 3a, a semiconductor layer 1a, and an insulating film 2 including a gate insulating film that insulates the gate electrode 3a from the semiconductor layer 1a. The gate electrode 3a is made of, for example, conductive polysilicon. The semiconductor layer 1a is made of, for example, polysilicon, and includes a channel region 1a ′, a low concentration source region 1b and a low concentration drain region 1c, and a high concentration source region 1d and a high concentration drain region 1e. The TFT 30 preferably has an LDD structure. However, the TFT 30 may have an offset structure in which no impurity is implanted into the low concentration source region 1b and the low concentration drain region 1c. It may be a self-aligned type in which a high concentration source region and a high concentration drain region are formed by implanting the film.

  The gate electrode 3a of the TFT 30 is electrically connected to the scanning line 11a through a contact hole 12cv formed in the base insulating film 12 in a part 3b thereof. The base insulating film 12 is made of, for example, a silicon oxide film, and is formed on the entire surface of the TFT array substrate 10 in addition to the interlayer insulating function between the first layer and the second layer. Has a function of preventing changes in the element characteristics of the TFT 30 caused by the above.

  The TFT 30 according to the present embodiment is a top gate type, but may be a bottom gate type.

(3rd layer configuration-data lines, etc.)
The third layer is composed of a data line 6a and a relay layer 600.

  The data line 6a is formed as a three-layer film of aluminum, titanium nitride, and silicon nitride in order from the bottom. The data line 6 a is formed so as to partially cover the channel region 1 a ′ of the TFT 30. For this reason, the channel region 1 a ′ of the TFT 30 can be shielded from incident light from the upper layer side by the data line 6 a that can be disposed close to the channel region 1 a ′. The data line 6 a is electrically connected to the high concentration source region 1 d of the TFT 30 through a contact hole 81 that penetrates the first interlayer insulating film 41.

  The relay layer 600 is formed as the same film as the data line 6a. As shown in FIG. 5, the relay layer 600 and the data line 6a are formed so as to be separated from each other. The relay layer 600 is electrically connected to the high-concentration drain region 1 e of the TFT 30 through a contact hole 83 that penetrates the first interlayer insulating film 41.

  The first interlayer insulating film 41 is made of, for example, NSG (non-silicate glass). In addition, for the first interlayer insulating film 41, silicate glass such as PSG (phosphorus silicate glass), BSG (boron silicate glass), BPSG (boron phosphorus silicate glass), silicon nitride, silicon oxide, or the like can be used.

(Fourth layer configuration-storage capacity, etc.)
The fourth layer includes a storage capacitor 70. The storage capacitor 70 has a configuration in which a capacitor electrode 300 and a lower electrode 71 are disposed to face each other with a dielectric film 75 interposed therebetween. The capacitor electrode 300 is an example of the “upper electrode” in the present invention, and the lower electrode 71 is an example of the “lower electrode” in the present invention. The extending portion of the capacitor electrode 300 is electrically connected to the relay layer 600 through a contact hole 84 that penetrates the second interlayer insulating film 42.

  The capacitor electrode 300 or the lower electrode 71 is formed by stacking, for example, a metal simple substance including at least one of metals such as Al, Ti, Cr, W, Ta, and Mo, an alloy, a metal silicide, a polysilicide, and a nitride. Consists of things. For this reason, the channel region 1 a ′ of the TFT 30 can be more reliably shielded against incident light from the upper layer by the storage capacitor 70 that can be disposed close to the data line 6 a via the interlayer insulating film 42.

  In addition, as shown in FIG. 6, the capacitor electrode 300 is formed in a region smaller than the lower electrode 71 when viewed in plan on the TFT array substrate 10. That is, since the capacitor electrode 300 is not formed near the edge of the lower electrode 71 through the dielectric film 75, a short circuit may occur due to a manufacturing failure near the edge, or a defect may occur due to electric field concentration. The possibility can be reduced.

As shown in FIG. 6, the dielectric film 75 is formed in a non-opening region located in the gap of the opening region for each pixel when viewed in plan on the TFT array substrate 10, that is, almost formed in the opening region. It has not been. Therefore, even if the dielectric film 75 is an opaque film, it is not necessary to reduce the transmittance in the opening region. Therefore, the dielectric film 75 is formed of a silicon nitride film or the like having a high dielectric constant without considering the transmittance. For this reason, the dielectric film 75 can also function as a film for preventing moisture and moisture, and can also improve water resistance and moisture resistance. In addition to the silicon nitride film, for example, a single layer film or a multilayer film such as hafnium oxide (HfO ₂ ), alumina (Al ₂ O ₃ ), tantalum oxide (Ta ₂ O ₅ ), or the like is used as the dielectric film. Also good.

  Here, the capacitor electrode 300, the lower electrode 71, and the dielectric film 75 are formed of an insulating film that forms an MIM element included in the electrostatic protection circuit 410 shown in FIG. 3 and a metal film that sandwiches the insulating film and a substrate. 10 is formed in the same layer. Therefore, the MIM element can be formed by the same film formation process using the material for forming the capacitor electrode 300, the lower electrode 71, and the dielectric film 75, so that the storage capacitor can be formed without greatly changing the design of the liquid crystal device 1. An MIM element can be easily formed using the same process as the process.

  The second interlayer insulating film 42 is made of, for example, NSG. In addition, for the second interlayer insulating film 42, silicate glass such as PSG, BSG, or BPSG, silicon nitride, silicon oxide, or the like can be used. The surface of the second interlayer insulating film 42 is subjected to a planarization process such as a chemical polishing process (CMP), a polishing process, a spin coat process, or a recess embedding process. Therefore, the unevenness caused by these elements on the lower layer side is removed, and the surface of the second interlayer insulating layer 42 is flattened. For this reason, the possibility of causing disturbance in the alignment state of the liquid crystal layer 50 sandwiched between the TFT array substrate 10 and the counter substrate 20 can be reduced, and higher-quality display can be achieved. Such planarization may be performed on the surface of another interlayer insulating film.

(Fifth layer configuration-pixel electrode, etc.)
A third interlayer insulating film 43 is formed on the entire surface of the fourth layer, and a pixel electrode 9a is formed thereon as a fifth layer. The third interlayer insulating film 43 is made of, for example, NSG. In addition, the third interlayer insulating film 43 can be made of silicate glass such as PSG, BSG, or BPSG, silicon nitride, silicon oxide, or the like. The surface of the third interlayer insulating film 43 is subjected to a planarization process such as CMP similarly to the second interlayer insulating film 42.

  The pixel electrode 9a (indicated by the broken line 9a 'in FIG. 6) is arranged in each of the pixel areas that are partitioned and arranged vertically and horizontally, and the data lines 6a and the scanning lines 11a are arranged in a grid at the boundary. (See FIGS. 5 and 6). The pixel electrode 9a is made of a transparent conductive film such as ITO (Indium Tin Oxide).

  The pixel electrode 9a is electrically connected to the extending portion of the capacitor electrode 300 through a contact hole 85 that penetrates the interlayer insulating film 43 (see FIG. 8). Therefore, the potential of the capacitor electrode 300, which is the conductive film immediately below the pixel electrode 9a, is the pixel potential. Therefore, the pixel potential is not adversely affected by the parasitic capacitance between the pixel electrode 9a and the underlying conductive film during the operation of the liquid crystal device.

  Further, as described above, the extended portion of the capacitor electrode 300 and the relay layer 600 and the relay layer 600 and the high-concentration drain region 1e of the TFT 30 are electrically connected through the contact holes 84 and 83, respectively. ing. That is, the pixel electrode 9a and the high-concentration drain region 1e of the TFT 30 are relay-connected through the relay layer 600 and the extended portion of the capacitor electrode 300. Accordingly, it is possible to avoid a situation in which it is difficult to connect the pixel electrode and the drain with a single contact hole due to a long interlayer distance. In addition, the laminated structure and the manufacturing process are not complicated.

  An alignment film 16 that has been subjected to a predetermined alignment process such as a rubbing process is provided above the pixel electrode 9a.

  The above is the configuration of the pixel portion on the TFT array substrate 10 side.

  On the other hand, the counter substrate 20 is provided with a counter electrode 21 on the entire surface of the counter substrate 20, and an alignment film 22 is further provided thereon (under the counter electrode 21 in FIG. 8). As with the pixel electrode 9a, the counter electrode 21 is made of a transparent conductive film such as an ITO film. A light-shielding film 23 is provided between the counter substrate 20 and the counter electrode 21 so as to cover at least a region facing the TFT 30 in order to prevent generation of light leakage current in the TFT 30.

  A liquid crystal layer 50 is provided between the TFT array substrate 10 thus configured and the counter substrate 20. The liquid crystal layer 50 is formed by sealing liquid crystal in a space formed by sealing the peripheral portions of the substrates 10 and 20 with a sealing material. The liquid crystal layer 50 takes a predetermined alignment state by the alignment film 16 and the alignment film 22 that have been subjected to an alignment process such as a rubbing process in a state where an electric field is not applied between the pixel electrode 9 a and the counter electrode 21. It is like that.

  The configuration of the pixel portion described above is common to each pixel portion as shown in FIGS. Such pixel portions are periodically formed in the image display region 10a (see FIG. 1). On the other hand, in such a liquid crystal device, as described with reference to FIGS. 1 and 2, the scanning line driving circuit 104, the data line driving circuit 101, and the like are driven in the peripheral area located around the image display area 10a. A circuit is formed.

<Configuration of electrostatic protection circuit>
Next, the configuration of the electrostatic protection circuit 410 shown in FIG. 3 will be described with reference to FIGS. 9 to 14.

<Operational principle of MIM element>
First, the operation principle of the MIM element included in the electrostatic protection circuit 410 will be described with reference to FIGS. 9 to 11. FIG. 9 is a circuit diagram of a PN diode 200 having terminals a1 and a2 and an MIM element 300 having terminals b1 and b2. FIG. 10A is a characteristic diagram showing the current-voltage characteristics of the PN diode, and FIG. 10B is a characteristic chart showing the current-voltage characteristics of the MIM element.

  9A, when the potential of the terminal a1 becomes higher with respect to the potential of the terminal a2 (that is, when a voltage is applied in the forward direction to the PN diode 200 in FIG. 10A), the PN diode 200 Causes a current to flow in the forward direction from the terminal a1 to the terminal a2. On the other hand, when the potential of the terminal A2 becomes higher with respect to the terminal a1 (that is, when a voltage is applied to the PN diode 200 in the reverse direction in FIG. 10A), no current flows through the diode 200. Therefore, the PN diode 200 is an element having an asymmetric current-voltage characteristic that allows a current to flow only in the forward direction (one direction) as shown in FIG.

  On the other hand, in FIG. 9B and FIG. 10B, the MIM element 300 is an element that allows a current to flow when the potential difference between the terminals b1 and b2 becomes a certain threshold voltage Vth or more with reference to the potential of the terminal b2. It is. More specifically, in FIG. 10B, when the potential of the terminal b1 becomes equal to or higher than the positive threshold voltage Vth + with respect to the terminal b2, a current flows from the terminal b1 to the terminal b2. On the other hand, when the potential of the terminal b1 becomes equal to or lower than the negative threshold voltage Vth− with respect to the terminal b2, a current flows from the terminal b2 toward the terminal b1. Therefore, unlike the PN diode 200, the MIM element 300 is an element having a symmetrical current-voltage characteristic that allows current to flow in both directions between the terminals b1 and b2. In addition, the MIM element 300 can pass a current only when the voltage applied between both electrodes exceeds a certain threshold voltage, and a voltage within the range of positive and negative threshold voltages is applied between both electrodes. In such a state, current does not flow.

  Such a current-voltage characteristic of the MIM element 300 is explained by a pool-Frankel effect described with reference to FIG. FIG. 11 is a diagram schematically showing an energy band structure near the junction interface between the terminal of the MIM element and the insulating film. The MIM element has a three-layer structure including a pair of electrodes formed of a metal material and an insulating film having an insulating film sandwiched between these electrodes.

  In FIG. 11, there is a trap level slightly lower than the intrinsic Fermi level Ei at the center of the band gap near the junction interface between the terminal of the MIM element and the insulating film. In a state in which a strong electric field of a certain value or more is applied between the pair of electrodes, the energy level of the conduction band Ec is partially increased by the Coulomb well generated in the Coulomb force based on the positive charge of the hole h + trapped in the trap level. A low energy level is formed, and the potential of the conduction band Ec with respect to the electron e- is lowered. As a result, a current flows through the MIM element having a three-layer structure including a metal, an insulating film, and a metal.

  Note that the relationship of the current I flowing through the MIM element due to the Pool-Frankel effect when the voltage V is applied between both electrodes is generally expressed by the following equation (1).

  As will be described in detail below, in the present embodiment, the electrostatic protection circuit 410 is configured by applying such current-voltage characteristics of the MIM element.

<Principle configuration of electrostatic protection circuit>
The principle configuration of the electrostatic protection circuit 410 will be described with reference to FIG. FIG. 12 is a circuit diagram showing the main part of the electrical connection configuration of the electrostatic protection circuit 410, the signal wiring 92, and the power supply line 93. In the present embodiment, an electrostatic protection circuit including only one MIM element is taken as an example, but it goes without saying that the electrostatic protection circuit 410 may include a plurality of MIM elements. In the present embodiment, a wiring signal for supplying the image signal VID to the data line driving circuit 101 is taken as an example of the signal wiring 92. However, the signal wiring 92 to which the MIM element 411 is connected includes the precharging selection signal NRG, Any signal wiring may be used for supplying any one of the input signals such as the enable signals EMB1 to EMB4, the start pulses DX and DY, the clock signals CLX and CLY, the inverted clock signal CLXB, and the counter electrode potential signal LCCOM. In addition, the power supply line 93 connected to the MIM element 411 may be a power supply line for supplying any one of the power supply line 93 s for supplying the low potential power supply and the high potential power supply 93 d. More specifically, the power supply line 93s connected to the MIM element 411 may be a power supply line for supplying any one of the second power supply signals VSSX1, VSSX2, VSSSX3, and VSSY. The power supply line 93d connected to 411 may be a power supply line for supplying any one of the first power supply signals VDDX1, VDDX2, VDDX3, and VDDY.

  In the present embodiment, the case where the power line 93s is connected to the MIM element 411 will be described first, and then the case where the power line 93d is connected to the MIM element 411 will be described.

  First, the case where the power supply line 93s is connected to the MIM element 411 will be described. In FIG. 12, the electrostatic protection circuit 410 has an MIM element 411, and both electrodes of the MIM element 411 are connected to the low-potential power line 93s and the signal wiring 92 through connection points A and B, respectively. Electrically connected.

  The MIM element 411 provides an electrical path for releasing the static electricity applied to the signal wiring 92 to the power supply line 93s based on the current-voltage characteristic defined by the pool-Frankel effect. More specifically, the positive threshold voltage Vth + and the negative threshold voltage Vth− of the MIM element 411 are input to the potential of the connection point A, the image signal VID, and the like within the range of potentials defined by these threshold voltages. The potential of the signal is set to be included, and no current flows through the MIM element 411 during the normal operation of the liquid crystal device 1.

  Next, a case where static electricity is applied to the signal wiring 92 will be described. When the electrostatic potential applied to the signal wiring 92 via the external circuit connection terminal 102 is higher than the positive threshold voltage Vth +, the MIM element 411 causes a current to flow from the signal wiring 92 to the power supply line 93s so as to release the static electricity. . Thereby, it is possible to reduce the possibility that the internal circuit unit configured by the data line driving circuit 101 and the like is electrostatically damaged by static electricity. However, in the MIM element 411, static electricity having a negative potential is applied to the signal wiring 92 in order to prevent current from flowing through the MIM element 411 during the normal operation of the liquid crystal device 1 due to its symmetrical current-voltage characteristics. In such a case, it is difficult for a current to flow to the power supply line 93s to flow negative static electricity.

  Next, the case where the power supply line 93d is connected to the MIM element 411 will be described. In FIG. 12, the MIM element 411 provides an electric path for releasing static electricity applied to the signal wiring 92 to the power supply line 93d based on a current-voltage characteristic defined by the pool-Frankel effect. More specifically, the positive threshold voltage Vth + and the negative threshold voltage Vth− of the MIM element 411 are input to the potential of the connection point A, the image signal VID, and the like within the range of potentials defined by these threshold voltages. The potential of the signal is set to be included, and no current flows through the MIM element 411 during the normal operation of the liquid crystal device 1.

  Next, a case where static electricity is applied to the signal wiring 92 will be described. When the electrostatic potential applied to the signal wiring 92 via the external circuit connection terminal 102 is lower than the negative threshold voltage Vth−, the MIM element 411 sends a current from the power supply line 93d to the signal wiring 92 so as to release the static electricity. Shed. Thereby, it is possible to reduce the possibility that the internal circuit unit configured by the data line driving circuit 101 and the like is electrostatically damaged by static electricity. However, the MIM element 411 is applied with static electricity having a positive potential to the signal wiring 92 in order to prevent current from flowing through the MIM element 411 during the normal operation of the liquid crystal device 1 due to its symmetrical current-voltage characteristics. In such a case, it is difficult for a current to flow through the positive side static electricity to the power supply line 93d.

<Specific configuration of MIM element>
Next, a specific configuration of the MIM element 411 included in the electrostatic protection circuit 410 will be described with reference to FIGS. 13 and 14. 13 is a plan view of the MIM element 411, and FIG. 14 is a cross-sectional view taken along the line XIV-XIV ′ of FIG.

  In FIG. 13, the MIM element 411 includes an electrode 71 a that is an example of the “first metal film” of the present invention and a power supply line 93 that is also used as an example of the “second metal film” of the present invention. The power line 93 may be either a power line 93 s for supplying a low potential power signal or a power line 93 d for supplying a high potential power signal.

  The electrode 71a and the power supply line 93 are formed so as to overlap each other in a plane. The electrode 71 a is electrically connected to a signal wiring 92 that is electrically connected to the external circuit connection terminal 102.

  In FIG. 14, an electrode 71a formed on the second interlayer insulating film 42 formed on the substrate 10 and formed in the same layer as the lower electrode 71 constituting the storage capacitor 70 shown in FIG. A power supply line 93 formed in the same layer as 300 and an insulating film 75a formed in the same layer as the dielectric film 75 are interposed between the electrode 71a and the power supply line 93. Each of the electrode 71a and the power line 93 is formed in the same process using the same material as the lower electrode 71 and the capacitor electrode 300. For example, aluminum (Al), titanium (Ti), tantalum (Ta), chromium It is formed using a metal material such as (Cr) or tungsten (W) or a material having an electrical property equivalent to that of a metal material such as titanium nitride (TiN) or tungsten silicide. The materials forming the electrode 71a and the power supply line 93 are preferably formed of the same material, but may be formed of different materials as long as symmetrical current-voltage characteristics can be obtained. Good.

  Such an MIM element 411 can form the electrode 71a, the insulating film 75a, and the power supply line 93 by using the process of forming the storage capacitor 70, so that the design of the liquid crystal device 1 is not greatly changed, and the liquid crystal device 1 It is formed without complicating the manufacturing process.

  In addition, since the electrode 71a, the insulating film 75a, and the power supply line 93 are formed in different layers and overlap with each other in a plane, the element size viewed in a plane can be made smaller than that of a semiconductor element such as a MOS TFT. More specifically, the MIM element 411 is a semiconductor element such as a MOSTFT in which the impurity region and the diffusion region spread in a plane in the semiconductor layer because the electrode 71a, the insulating film 75a, and the power supply line 93 overlap in a plane. Compared to the size can be reduced. Therefore, the MIM element 411 is formed without any restriction on the layout of the data line driving circuit or the like in a small electro-optical device or an electro-optical device in which the image display area occupies most of the area on the substrate. In addition, according to the MIM element 411, it is not necessary to electrically connect the semiconductor layer and the electrode via a contact hole unlike a semiconductor element such as a MOS TFT, so that the manufacturing process of the electro-optical device is complicated. In addition, it is possible to provide an electro-optical device in which the possibility of electrostatic breakdown of an internal circuit unit including a data line driving circuit or the like is effectively reduced.

  In the liquid crystal device 1 of the present embodiment, a part of the signal wiring 92 and the power supply line 93 may be used as a part of the MIM element 411 as it is, for example, from the main line part of the signal wiring 92 and the power supply line 93. You may form by the part which protruded partially. According to the liquid crystal device 1 of the present embodiment, since the MIM element can be formed by a part of the signal wiring 92 and the power supply line 93, the MIM element can be formed without complicating the layout of the wiring formed on the substrate 10. Can be formed.

(Second Embodiment)
Next, an embodiment of the electro-optical device according to the second invention of the present invention will be described with reference to FIGS. The liquid crystal device of this embodiment is characterized in that the configuration of the electrostatic protection circuit is different from that of the liquid crystal device of the first embodiment.

<Principle configuration of electrostatic protection circuit>
With reference to FIG. 15, an electrical connection configuration of the electrostatic protection circuit 510 included in the liquid crystal device of the present embodiment will be described.

  15, the electrostatic protection circuit 510 includes an MIM element 411s electrically connected to the signal wiring 92 and the power supply line 93s, and an MIM element 411d electrically connected to the signal wiring 92 and the power supply line 93d. ing. Both electrodes of the MIM element 411s are electrically connected to the low-potential power supply line 93s and the signal wiring 92 via connection points C and D, respectively.

  The threshold voltage Vth + on the positive side and the threshold voltage Vth− on the negative side of the MIM element 411s are the potential of the connection point C and the potential of the connection point D within the range of potentials defined by these threshold voltages. It is set to include the potential of the input signal, and no current flows through the MIM element 411s during normal operation of the liquid crystal device. Similarly, the positive-side threshold voltage Vth + and the negative-side threshold voltage Vth− of the MIM element 411d are image signals that are the potential at the connection point E and the potential at the connection point D within the range of potentials defined by these threshold voltages. The input signal potential such as VID is set to be included, and no current flows through the MIM element 411d during normal operation of the liquid crystal device. Therefore, in the normal operation of the liquid crystal device, the signal wiring 92 is not electrically connected to the power supply line 93s and the power supply line 93d.

  Next, the operation of the MIM elements 411s and 411d when static electricity is applied to the signal wiring 92 will be described. When static electricity having a higher potential than the input signal such as the image signal VID is applied to the signal wiring 92, the MIM element 411s causes the static electricity to be applied to the power supply line 93s based on the current-voltage characteristics defined by the Pool-Frankel effect. Provide an electrical path to escape. When static electricity having a lower potential than the input signal such as the image signal VID is applied to the signal wiring 92, the MIM element 411 d is applied to the signal wiring 92 based on the current-voltage characteristic defined by the pool-Frankel effect. An electric path for releasing the applied static electricity to the power supply line 93d is provided. Thereby, according to the electrostatic protection circuit 510 included in the liquid crystal device of the present embodiment, static electricity having a potential higher than the highest potential of the input signal input to the signal wiring 92 and static electricity having a potential lower than the lowest potential of the input signal. Can be effectively released to the power supply lines 93s and 93d via the MIM elements 411s and 411d, respectively.

  Therefore, according to the electrostatic protection circuit 510 included in the liquid crystal device according to the present embodiment, it is possible to escape from the signal wiring 92 to the power supply line 93 as compared with the electrostatic protection circuit 410 included in the liquid crystal device according to the first embodiment. The range of the potential of static electricity that can be generated can be expanded, and the possibility that the internal circuit portion including the data line driving circuit and the like is electrostatically damaged can be more effectively reduced.

<Specific configuration of MIM element>
Next, specific configurations of the MIM elements 411s and 411d will be described with reference to FIGS. 16 is a plan view of the MIM elements 411s and 411d, and FIG. 17 is a cross-sectional view taken along the line XVII-XVII ′ of FIG.

  In FIG. 16, the MIM element 411d includes an electrode 71b which is an example of the “first metal film” of the present invention and an electrode 94d which is an example of the “second metal film” of the present invention.

  The electrode 71 b is formed in the same layer as the signal wiring 92 and is formed in the same process as the signal wiring 92. The electrode 71b is a portion where the signal wiring 92 is extended, but may be electrically connected to the signal wiring 92. The electrode 94d is formed in the same layer as the power line 93d for supplying a high potential power signal formed in a layer different from that of the electrode 71b. In the present embodiment, the electrode 94d is a portion where the power line 93d is extended. The electrode 94d is formed to overlap the electrode 71b in plan view.

  The MIM element 411s includes an electrode 71c, which is an example of “the other part of the first metal film” of the present invention, and an electrode 94s, which is an example of the “third metal film” of the present invention.

  The electrode 71 c is formed in the same layer as the signal wiring 92 and is formed in the same process as the signal wiring 92. The electrode 71c is a portion where the signal wiring 92 is extended, but may be electrically connected to the signal wiring 92. The electrode 94s is formed in the same layer as the power line 93s for supplying a low potential power signal formed in a layer different from that of the electrode 71d. In the present embodiment, the electrode 94s is a portion where the power line 93s is extended, and is formed so as to overlap the electrode 71c in plan view.

  In FIG. 17, the MIM element 411d includes a portion 75d extending between the electrodes 94d and 71b in the insulating film 75b formed on the second interlayer insulating film 42 as an example of the “first insulating film” in the present invention. . Therefore, the MIM element 411d has a three-layer structure including the electrode 94d, the insulating film 75d, and the electrode 71b. The MIM element 411 s includes a portion 75 s extending between the electrodes 94 s and 71 c in the insulating film 75 b formed on the second interlayer insulating film 42 as an example of the “second insulating film” in the present invention. Therefore, the MIM element 411s has a three-layer structure including the electrode 94s, the insulating film 75s, and the electrode 71c. The electrodes 94d and 94s are formed in the same layer as the capacitor electrode 300 shown in FIG. 8, and are formed using the same material and the same process as the capacitor electrode 300. The electrodes 94 and 94s can be formed by partially etching the electrode film formed on the insulating film 75b together with the capacitor electrode 300. At this time, a portion 75e of the insulating film 71c extending near the center in the drawing functions as an etching stopper for protecting the signal wiring 92 so that the signal wiring 92 is not etched. Note that the insulating film 71c may be formed in a state where the portion 75e extending near the center in the drawing is removed, or the electrodes 94d and 94s may be separated from each other.

  The electrodes 94s and 94d and the electrode 71b are, for example, metal materials such as aluminum (Al), titanium (Ti), tantalum (Ta), chromium (Cr), tungsten (W), titanium nitride (TiN), tungsten silicide, etc. It is formed using a material having an electrical property equivalent to that of the metal material. The materials for forming the electrodes 94s and 94d and the electrode 71b are preferably formed of the same material, but are formed of different materials so that symmetrical current-voltage characteristics can be obtained. May be.

  In the MIM elements 411d and 411s, the electrodes 94s and 94d may be formed below the insulating film 75b, and the electrode 71b may be formed above the insulating film 75b.

  According to the MIM elements 411s and 411d included in the liquid crystal device of the present embodiment, the electrodes 94s and 94d and the insulating film 75c can be formed when the electrode structure and the dielectric film constituting the storage capacitor 70 are formed. As in the embodiment, the MIM element is formed without greatly changing the design of the liquid crystal device and without complicating the manufacturing process of the liquid crystal device.

  In addition, since the electrodes 94s and 94d, the electrode 71b, and the insulating film 75b are formed in different layers and overlap in a plane, the element size in a plane is smaller than that of a semiconductor element such as a MOS TFT. it can. Therefore, the MIM elements 411d and 411s are formed without restricting the layout of the data line driving circuit or the like in a small electro-optical device or an electro-optical device in which the image display area occupies most of the area on the substrate. The In addition, according to the MIM elements 411s and 411d, it is not necessary to electrically connect the semiconductor layer and the electrodes through the contact holes unlike the semiconductor elements such as MOSTFT, so that the manufacturing process of the electro-optical device is complicated. Thus, it is possible to provide an electro-optical device in which the possibility of electrostatic breakdown of the internal circuit portion including the data line driving circuit and the like is effectively reduced.

(Modification)
Next, a modified example of the MIM element included in the liquid crystal device of the present embodiment will be described with reference to FIGS.

  18 is a plan view showing a configuration of a modified example of the MIM element, and FIG. 19 is a cross-sectional view taken along line XIX-XIX ′ of FIG.

  18 and 19, in the MIM element 411d and the MIM element 411s, a part of the power supply lines 93s and 93d is also used as an electrode of each element as it is. Of the electrode 171 formed in the same layer as the signal wiring 92, a portion overlapping the power supply line 93s is one electrode 71c of the MIM element 411s, and a portion overlapping the power supply line 93d is one electrode 71b of the MIM element 411d. Yes.

  The electrode 171 is formed in the same layer as the signal wiring 92 and is formed in the same process as the signal wiring 92. The electrode 171 is a portion where the signal wiring 92 is extended, but may be electrically connected to the signal wiring 92. The MIM element 411d has an insulating film 75d that is a portion extending between the electrode 71d and the power supply line 93d in the insulating film 75b formed on the power supply lines 93s and 93d, and the electrode 71d, the power supply line 93d, and the insulating film. The MIM element 411d is formed by 75d. Similarly, the MIM element 411s is formed by an electrode 71s, an insulating film 75s, and a power supply line 93s.

  According to the MIM elements 411s and 411d having such a configuration, as in the case described with reference to FIGS. 16 and 17, the electrostatic protection circuit including the MIM element formed by a simple manufacturing process allows the signal to be generated. Static electricity applied to the wiring can be released to the power supply line, and the possibility that the internal circuit portion including the data line driving circuit and the like is electrostatically damaged can be effectively reduced.

(Electronics)
Next, the case where the above-described liquid crystal device is applied to various electronic devices will be described.

  First, a projector using this liquid crystal device as a light valve will be described. FIG. 20 is a plan view showing a configuration example of the projector. As shown in FIG. 20, 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 this dichroic prism 1112, R and B light is refracted at 90 degrees, while G light travels straight. Accordingly, 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, 1110B.

  Note that since light corresponding to the primary colors 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.

  Next, an example in which the liquid crystal device is applied to a mobile personal computer will be described. FIG. 21 is a perspective view showing the configuration of this personal computer. In FIG. 21, the computer 1200 includes a main body 1204 having a keyboard 1202 and a liquid crystal display unit 1206. The liquid crystal display unit 1206 is configured by adding a backlight to the back surface of the liquid crystal device 1005 described above.

  Further, an example in which the liquid crystal device is applied to a mobile phone will be described. FIG. 22 is a perspective view showing the configuration of this mobile phone. In FIG. 22, a mobile phone 1300 includes a reflective liquid crystal device 1005 together with a plurality of operation buttons 1302. In the reflective liquid crystal device 1005, a front light is provided on the front surface thereof as necessary.

  In addition to the electronic devices described with reference to FIGS. 20 to 22, a liquid crystal television, a viewfinder type, a monitor direct view type video tape recorder, a car navigation device, a pager, an electronic notebook, a calculator, a word processor, a work Examples include a station, a videophone, a POS terminal, a device equipped with a touch panel, and the like. Needless to say, the present invention can be applied to these various electronic devices.

  The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit or concept of the invention that can be read from the claims and the entire specification. An electronic apparatus including the electro-optical device is also included in the technical scope of the present invention. More specifically, the electro-optical device according to the first and second inventions of the present invention, or the electronic apparatus according to the present invention, is variously transmissive, reflective, and self-conducting, such as LCOS, DMD, and organic EL device. It can be applied to a light emitting device.

1 is a plan view illustrating a configuration of an electro-optical device according to a first embodiment. It is the HH 'sectional view taken on the line of FIG. 1 is a diagram illustrating a configuration of a main part of an electro-optical device according to a first embodiment. FIG. 3 is an equivalent circuit diagram of various elements, wirings, and the like in the pixel portion of the electro-optical device according to the first embodiment. It is a figure which shows a lower layer part among the laminated structure of the electro-optical apparatus which concerns on 1st Embodiment. It is a figure which shows the upper layer part among the laminated structure of the electro-optical apparatus which concerns on 1st Embodiment. FIG. 7 is an enlarged view in which FIGS. 5 and 6 are superimposed. FIG. 8 is a cross-sectional view taken along line AA ′ in FIG. 7. It is a circuit diagram of a PN diode and an MIM element. It is the characteristic view which showed the electric current 0-voltage characteristic of a PN diode and an MIM element. It is the figure which showed typically the energy band structure near the junction interface of the terminal of an MIM element, and an insulating film. FIG. 3 is a circuit diagram illustrating a main part of an electrical connection configuration of an MIM element, a signal wiring, and a power supply line in the electro-optical device according to the first embodiment. 3 is a plan view of an MIM element included in the electro-optical device according to the first embodiment. FIG. It is the XIV-XIV 'sectional view taken on the line of FIG. FIG. 10 is a circuit diagram illustrating a main part of an electrical connection configuration of an MIM element, a signal wiring, and a power supply line in an electro-optical device according to a second embodiment. FIG. 6 is a plan view of an MIM element included in an electro-optical device according to a second embodiment. It is the XVII-XVII 'sectional view taken on the line of FIG. It is a top view which shows the modification of the MIM element with which the liquid crystal device which concerns on 2nd Embodiment is provided. It is the XIX-XIX 'sectional view taken on the line of FIG. 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. 1 is a perspective view showing a configuration of a personal computer as an example of an electronic apparatus to which an electro-optical device is applied. It is a perspective view which shows the structure of the mobile telephone which is an example of the electronic device to which the electro-optical apparatus is applied.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Liquid crystal device 10, ... Board | substrate, 75a, 75b ... Insulating film, 92 ... Signal wiring, 93 ... Power supply line, 410 ... Electrostatic protection circuit, 411 ... MIM element

Claims (9)

A substrate,
A plurality of pixel portions formed in a pixel region on the substrate; and a peripheral circuit portion formed in a peripheral region located around the pixel region and for controlling the pixel portion;
Signal wiring for electrically connecting the peripheral circuit part and input terminals for inputting input signals to the peripheral circuit part;
A power supply line for supplying a power supply potential to the peripheral circuit section;
A first metal film formed on the substrate and electrically connected to the signal wiring, and formed in a layer different from the first metal film so as to overlap the first metal film in plan view. And a second metal film electrically connected to the power supply line, and an electrostatic protection circuit comprising an MIM element formed by the first metal film and an insulating film interposed between the second metal film. An electro-optical device characterized by the above. The pixel unit includes a storage capacitor in which a lower electrode, a dielectric film, and an upper electrode are sequentially stacked on the substrate.
Each of the first metal film and the second metal film is formed in the same layer as the metal film constituting each of the lower electrode and the upper electrode,
The electro-optical device according to claim 1, wherein the insulating film is formed in the same layer as the dielectric film. The electro-optical device according to claim 1, wherein each of the first metal film and the second metal film is a part of a metal film constituting each of the signal wiring and the power supply line. . The power supply line is a low potential power supply line that supplies a low potential power supply having a potential lower than the potential of the signal wiring to the peripheral circuit unit,
The electro-optical device according to any one of claims 1 to 3, wherein the second metal film is electrically connected to the low-potential power line. The power supply line is a high potential power supply line that supplies a high potential power supply having a potential higher than the potential of the signal wiring to the peripheral circuit unit,
The electro-optical device according to any one of claims 1 to 3, wherein the second metal film is electrically connected to the high-potential power line. A substrate,
A plurality of pixel portions formed in a pixel region on the substrate; and a peripheral circuit portion formed in a peripheral region located around the pixel region and for controlling the pixel portion;
Signal wiring for electrically connecting the peripheral circuit part and input terminals for inputting input signals to the peripheral circuit part;
A high potential power supply line for supplying a power supply potential higher than a predetermined potential to the peripheral circuit portion, and a low potential power supply line for supplying a power supply potential lower than the predetermined potential;
A part of the first metal film electrically connected to the signal wiring on the substrate, and a layer different from the first metal film so as to overlap the part in plan view; and A first MIM element formed by a second metal film electrically connected to a high-potential power line, a first insulating film interposed between the part and the second metal film, and the first metal film. And a third metal film formed in the separate layer so as to overlap the other part in plan view and electrically connected to the low-potential power line, and the other part and the first part. An electro-optical device comprising: an electrostatic protection circuit comprising: a second MIM element formed by a second insulating film interposed between three metal films. The pixel unit includes a storage capacitor in which a lower electrode, a dielectric film, and an upper electrode are sequentially stacked on the substrate.
The first metal film, the second metal film, and the third metal film are formed in the same layer as a metal film constituting each of the lower electrode and the upper electrode,
The electro-optical device according to claim 6, wherein the first insulating film and the second insulating film are formed in the same layer as the dielectric film. The electro-optical device according to claim 6, wherein the second metal film and the third metal film are formed by partially removing the metal film. An electronic apparatus comprising the electro-optical device according to any one of claims 1 to 8.

Images