JP2008233740A - Liquid crystal device and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a numerical aperture of a liquid crystal device having, for example, a touch panel function. <P>SOLUTION: A photodiode 150 is disposed in a non-opening region, as a region which does not contribute to image display between a TFT array substrate 10 and a counter substrate 20 so as to keep the interval between the TFT array substrate 10 and counter substrate 20 constant, that is, the inter-substrate gap between those substrates. Since the photodiode 150 will not cause decrease in the numerical aperture of the pixels, image display of high quality can be obtained by the liquid crystal device 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to, for example, a technical field of a liquid crystal device having a touch panel function and an electronic apparatus including such a liquid crystal device.

  In this type of liquid crystal device, spacers are arranged between these substrates in order to maintain a constant distance between the TFT array substrate that sandwiches the liquid crystal layer and the counter substrate (so-called inter-substrate gap). For example, Patent Document 1 discloses a liquid crystal display device including columnar spacers. Patent Document 2 discloses a technique for reducing the positional deviation between the TFT array substrate and the counter substrate by disposing a convex spacer so as to overlap a concave portion formed in the counter substrate.

  On the other hand, this type of liquid crystal device has a touch panel function capable of inputting information by detecting that an input means such as a finger touches the display surface of the liquid crystal device or moves on the display surface. Are known. In such a liquid crystal device having a touch panel function, light incident from the display surface side is detected by a light receiving element arranged in a display region composed of a plurality of pixels, and an input means such as a finger touches the display surface, or It is configured to detect movement on the display surface and to input various information (see, for example, Patent Documents 3 to 6).

JP 2002-341355 A JP 2001-222234 A JP 2004-45875 A JP-A-5-333369 Japanese Patent Laid-Open No. 6-194681 JP-A-6-18846

  However, this type of liquid crystal device has a problem that the opening region contributing to image display cannot be expanded by the spacer disposed between the TFT array substrate and the counter substrate. More specifically, the spacer disposed between the TFT array substrate and the counter substrate interferes with the liquid crystal layer originally disposed at a position that should contribute to image display, and the TFT array substrate and the counter substrate are opposed to each other according to the size of the spacer. A region that should contribute to image display between the substrates is narrowed. Therefore, the ratio of the pixels on the TFT array substrate that can be substantially used as the opening region (that is, the opening ratio) is reduced. Such a problem is that even if the spacer is formed using a light-transmitting material, the liquid crystal occupies a region that should contribute to image display as long as the spacer is disposed between the substrates. This is a problem that is difficult to avoid because the region is narrowed.

  Further, in a liquid crystal device having a light receiving element, when the incident light that changes according to the movement of the input means such as a finger is detected by the light receiving element, the incident light cannot be condensed on the light receiving element. May not be detected accurately. Therefore, there may be a problem that information corresponding to the movement of the input means cannot be accurately detected via the display surface of the liquid crystal device. In addition, since light enters the display surface of the liquid crystal device from all directions toward the display surface, it may be difficult to detect the movement of the input means by the light receiving element. In particular, when the light sensitivity of the light receiving element is low, there is a high possibility that the movement of the input means is erroneously detected by the light receiving element, and the difficulty in detecting the movement of the input means becomes even more pronounced.

  Therefore, the present invention has been made in view of the above-described problems. For example, the opening has a touch panel function capable of accurately detecting the movement of an input unit such as a finger and substantially contributes to image display. It is an object of the present invention to provide a liquid crystal device capable of expanding a region, that is, improving an aperture ratio, and an electronic device including such a liquid crystal device.

  In order to solve the above problems, a liquid crystal device according to the present invention includes a substrate, a counter substrate disposed on the substrate so as to face the substrate, and a liquid crystal layer sandwiched between the substrate and the counter substrate. A light receiving element that is formed in a non-opening region that separates opening regions of a plurality of pixels that constitute a display region on the substrate, and that also serves as a spacer that defines a gap between the substrate and the counter substrate; Is provided.

  According to the liquid crystal device of the present invention, during the operation of the liquid crystal device, for example, the alignment of the liquid crystal layer sandwiched between the pixel electrode formed on the substrate and the counter electrode formed on the counter substrate is controlled. As a result, a desired image is displayed in the display area.

  The light receiving element is formed in a non-opening region that separates open regions of a plurality of pixels that form a display region on the substrate. Here, the “opening region” is defined by a light shielding film or wiring provided on the substrate, and is a region in a pixel through which light contributing to image display can be transmitted, or a reflection mode using external light. The display area. Conversely, a region in which a wiring, a light-shielding film, etc. are formed in the pixel and does not contribute to display, that is, a region separating the opening regions from each other is called a “non-opening region”.

  The light receiving element is also used as a spacer for defining a gap between the substrate and the counter substrate. According to such a light receiving element, since it is not necessary to arrange a spacer in the opening region, the liquid crystal layer is formed in the entire opening region. Therefore, according to the light receiving element, it is possible to reduce the formation of a region that does not contribute to image display in a part of the opening region by arranging the spacer in the opening region. Further, since the light receiving element is also used as a spacer, it is not necessary to provide a spacer separately from the light receiving element only to maintain the inter-substrate gap.

  Since such a light receiving element has higher rigidity than a spacer made of resin or the like, for example, the heights of a plurality of light receiving elements arranged on the substrate are aligned with each other in advance. As a result, it is possible to make the gap between the substrates uniform compared to the case where spacers made of resin or the like are arranged.

  Note that the light receiving element detects the movement of an input unit such as a finger on the display surface by detecting incident light incident from a display surface that is not facing the liquid crystal layer, for example, on both surfaces of the counter substrate.

  Therefore, according to the liquid crystal device according to the present invention, when the liquid crystal device is operated, the entire opening region is used as a region substantially contributing to image display, and the spacer is disposed between the substrate and the counter substrate. It becomes possible to improve the aperture ratio which falls by this. Therefore, according to the liquid crystal device of the present invention, it is possible to improve the display quality of an image. In addition, according to the liquid crystal device according to the present invention, since it is not necessary to provide a spacer separately from the light receiving element, the material cost and the manufacturing cost of the liquid crystal device can be reduced.

  In one aspect of the liquid crystal device according to the present invention, the light receiving element is a photodiode having a photodiode body, and an upper electrode and a lower electrode formed so as to be in contact with the upper surface and the lower surface of the photodiode body. There may be.

  According to this aspect, by detecting the photocurrent flowing through the photodiode, various information corresponding to the movement of the input means such as a finger can be input to the liquid crystal device.

  In this aspect, the pixel switching element provided for each pixel on the substrate, and a conductive layer electrically connected to the pixel switching element, at least one of the upper electrode and the lower electrode is provided. May be formed in the same layer as the conductive layer on the substrate.

  According to this aspect, the substrate is a TFT array substrate on which pixel switching elements such as TFTs (Thin Film Transistors) are formed. For example, the lower electrode is formed in the same layer as the conductive layer that is the source electrode, the drain electrode, or the gate electrode of the pixel switching element that is a transistor element such as a TFT. Therefore, according to this aspect, the lower electrode can be formed by a process common to the process of forming the source electrode and the like, and the lower electrode can be formed without complicating the manufacturing process.

  In another aspect of the invention, the photodiode is embedded in the planarization film so as to protrude from the planarization film formed on the pixel switching element toward the counter substrate, and the lower electrode May be formed on the lower layer side of the planarizing film.

  According to this aspect, the amount of photodiode embedded in the planarizing film or the size of the photodiode is adjusted, and the size of the portion of the photodiode protruding from the planarizing film toward the counter substrate is adjusted. Thus, the gap between the substrates can be defined.

  In another aspect of the liquid crystal device according to the present invention, the lower electrode is formed on a planarizing film that covers the pixel switching element and is in the same layer as the pixel electrode that is electrically connected to the pixel switching element. It may be formed.

  According to this aspect, for example, the lower electrode can be formed by a process common to a pixel electrode made of a transparent conductive material such as ITO, and a photodiode can be formed on the planarizing film. Therefore, not only can the manufacturing process of the liquid crystal device be complicated, but also the gap between the substrates can be accurately defined by adjusting the size of the photodiode.

  In another aspect of the liquid crystal device according to the present invention, the lower electrode is formed in the same layer as the common electrode common to the plurality of pixels, and the conductive layer is a layer different from the common electrode on the substrate. The upper electrode is a portion where the conductive layer extends to the upper surface, and the liquid crystal layer may be driven by a lateral electric field generated between the common electrode and the pixel electrode. .

  According to this aspect, the alignment state of the liquid crystal layer can be controlled by a lateral electric field driving method such as an IPS (In-Plane Switching) method or an FFS (Fringe Field Switching) method. The upper electrode is a portion where a conductive layer formed by a process common to the process of forming the pixel electrode extends to the upper surface of the photodiode. Therefore, the upper electrode can be formed by a process common to the process of forming the pixel electrode, and the manufacturing process of the liquid crystal device can be prevented from becoming complicated.

  In another aspect of the liquid crystal device according to the present invention, the lower electrode is formed in the same layer as a pixel electrode corresponding to each of the plurality of pixels, and the conductive layer is connected to the pixel electrode on the substrate. The upper electrode is a portion where the conductive layer extends to the upper surface, and the liquid crystal layer is driven by a lateral electric field generated between the common electrode and the pixel electrode. Also good.

  According to this aspect, the alignment state of the liquid crystal layer can be controlled by a lateral electric field driving method such as an IPS (In-Plane Switching) method or an FFS (Fringe Field Switching) method. The upper electrode is a portion where a conductive layer formed by a process common to the process of forming the common electrode extends to the upper surface of the photodiode. Therefore, the upper electrode can be formed by a process common to the process of forming the common electrode, and the manufacturing process of the liquid crystal device can be prevented from becoming complicated.

  In another aspect of the liquid crystal device according to the present invention, the upper electrode may be an electrode formed on a surface facing the liquid crystal layer among both surfaces of the counter substrate.

  According to this aspect, for example, when the substrate and the counter substrate are bonded to each other, the upper electrode previously formed on the counter substrate side is in contact with the upper surface of the photodiode body, thereby forming the photodiode. Therefore, not only the lower electrode and the photodiode body are set so as to define the target gap between the substrates, but also the fine adjustment of the gap between the substrates by adjusting the film thickness of the upper electrode and adjusting the bonding of the substrate and the counter substrate. Is possible.

  In addition, since the upper electrode is located immediately below the counter substrate or the color filter provided on the counter substrate, the light reflected by the input means such as a finger or the outside light not blocked by the input means is caused by the liquid crystal. The light is directly irradiated to a light receiving element such as a photodiode without being absorbed. Therefore, according to this aspect, various information can be accurately input to the liquid crystal device from the input unit without being affected by light absorption by the liquid crystal.

  In order to solve the above problems, an electronic device according to the present invention includes the above-described liquid crystal device of the present invention.

  According to the electronic apparatus according to the present invention, since the above-described liquid crystal device according to the present invention is included, the mobile phone, the electronic notebook, the word processor, and the monitor direct-view having a touch panel function and capable of high-quality display. Various electronic devices such as video tape recorders, workstations, videophones, and POS terminals 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 a liquid crystal device and an electronic apparatus according to the present invention will be described with reference to the drawings.

<1: Liquid crystal device>
<1-1: Overall Configuration of Liquid Crystal Device>
First, the overall configuration of the liquid crystal device 1 according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a plan view of the liquid crystal device 1 as viewed from the counter substrate side together with the components formed on the TFT array substrate, and FIG. 2 is a cross-sectional view taken along the line II-II ′ of FIG. The liquid crystal device 1 according to the present embodiment is driven by a TFT active matrix driving method with a built-in driving circuit.

  1 and 2, in the liquid crystal device 1, a TFT array substrate 10, which is an example of the “substrate” of the present invention, 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 positioned around an image display region 10a that is a display region in which a plurality of pixel portions are provided. They are bonded to each other by a sealing material 52 provided in the sealing area.

The sealing material 52 is made of, for example, an ultraviolet curable resin, a thermosetting resin, or the like for bonding the two substrates, and is applied on the TFT array substrate 10 in the manufacturing process and then cured by ultraviolet irradiation, heating, or the like. It is. In the sealing material 52, a gap material such as glass fiber or glass beads for dispersing the distance between the TFT array substrate 10 and the counter substrate 20 (inter-substrate gap) to a predetermined value is dispersed.

  A light-shielding frame light-shielding film 53 that defines the frame area of the image display area 10a is provided on the counter substrate 20 side in parallel with the inside of the seal area where the sealing material 52 is disposed. However, part or all of the frame light shielding film 53 may be provided as a built-in light shielding film on the TFT array substrate 10 side. There is a peripheral area located around the image display area 10a. In other words, particularly in the present embodiment, when viewed from the center of the TFT array substrate 10, the distance from the frame light shielding film 53 is defined as the peripheral region.

  A data line driving circuit 101 and an external circuit connection terminal 102 are provided along one side of the TFT array substrate 10 in a region located outside the sealing region where the sealing material 52 is disposed in the peripheral region. The scanning line driving circuit 104 is provided along two sides adjacent to the one side so as to be covered with the frame light shielding film 53. Further, in order to connect the two scanning line driving circuits 104 provided on both sides of the image display area 10 a in this way, a plurality of the pixel lines are covered along the remaining side of the TFT array substrate 10 and covered with the frame light shielding film 53. Wiring 105 is provided.

  Vertical conductive members 106 functioning as vertical conductive terminals between the two substrates are disposed at the four corners of the counter substrate 20. On the other hand, the TFT array substrate 10 is provided with vertical conduction terminals in a region facing these corner portions. Thus, electrical conduction can be established between the TFT array substrate 10 and the counter substrate 20. The counter electrode 21 is set to a fixed potential.

  In FIG. 2, on the TFT array substrate 10, an alignment film is formed on the pixel electrode 9a after the pixel switching TFT, the scanning line, the data line and the like are formed. On the other hand, on the counter substrate 20, in addition to the counter electrode 21, a lattice-shaped or striped light-shielding film 23 and an alignment film are formed on the uppermost layer portion. The liquid crystal layer 50 is made of, for example, a liquid crystal in which one or several types of nematic liquid crystals are mixed, and takes a predetermined alignment state between the pair of alignment films.

  1 and 2, on the TFT array substrate 10, in addition to the drive circuits such as the data line drive circuit 101 and the scanning line drive circuit 104, the image signal on the image signal line is sampled to obtain data. Sampling circuit that supplies lines, precharge circuit that supplies pre-charge signals of a predetermined voltage level to multiple data lines in advance of image signals, inspection of quality, defects, etc. of the electro-optical device during production or shipment An inspection circuit or the like may be formed.

<1-2: Configuration in Pixel Unit>
Next, the configuration of the pixel portion of the liquid crystal device 1 will be described in detail with reference to FIGS. 3 to 6. FIG. 3 is an equivalent circuit of various elements, wirings, and the like in a plurality of pixels formed in a matrix that forms the image display region 10a of the liquid crystal device 1. FIG. 4 shows data lines, scanning lines, pixel electrodes, FIG. 4 is a plan view of a plurality of pixel groups adjacent to each other on a formed TFT array substrate. 5 is a cross-sectional view taken along the line VV ′ of FIG. 6 is a cross-sectional view taken along the line VI-VI ′ of FIG. In FIGS. 5 and 6, the scale of each layer / member is different for each layer / member to have a size recognizable on the drawing.

  In FIG. 3, a pixel electrode 9 a and a TFT 30 are formed in each of a plurality of pixels formed in a matrix constituting the image display region 10 a of the liquid crystal device 1. The TFT 30 is electrically connected to the pixel electrode 9a, and performs switching control of the pixel electrode 9a when the liquid crystal device 1 operates. 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 3a is electrically connected to the gate of the TFT 30, and the liquid crystal device 1 sequentially applies the scanning signals G1, G2,..., Gm to the scanning line 3a in a pulse sequence in this order at a predetermined timing. It is comprised so that it may apply. 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. Image signals S1, S2,..., Sn written to the liquid crystal via the pixel electrode 9a are held for a certain period with the counter electrode formed on the counter substrate.

  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 transmittance for light is increased, and light having a contrast corresponding to an image signal is emitted from the liquid crystal device as a whole. The storage capacitor 70 is added in parallel with the liquid crystal capacitor formed between the pixel electrode 9a and the counter electrode in order to prevent the image signal from leaking.

  Next, a specific configuration of the pixel portion will be described with reference to FIGS.

  In FIG. 4, on the TFT array substrate 10 of the liquid crystal device 1, a plurality of transparent pixel electrodes 9a (outlined by dotted line portions 9a ′) are provided in a matrix in the X direction and the Y direction. A data line 6a and a scanning line 3a are provided along the vertical and horizontal boundaries of the pixel electrode 9a. The liquid crystal device 1 includes a photodiode 150, which is an example of the “light receiving element” of the present invention, provided in a non-opening region where a non-transparent film such as the data line 6 a and the scanning line 3 a is formed on the TFT array substrate 10. Have.

  In the semiconductor layer 1a, the scanning line 3a is arranged so as to face the channel region 1a 'indicated by the hatched region rising to the right in FIG. As described above, the pixel switching TFT 30 is provided at each of the intersections of the scanning line 3a and the data line 6a.

  The data line 6 a is formed on the base film 42 aa formed using the second interlayer insulating film 42 whose upper surface is flattened as a base, and is connected to the high concentration source region of the TFT 30 through the contact hole 81. Yes. The data line 6a and the inside of the contact hole 81 are made of, for example, an Al (aluminum) -containing material such as Al—Si—Cu or Al—Cu, Al alone, or a multilayer film including an Al layer and a TiN layer. The data line 6a has a function of shielding the TFT 30 from light.

  The storage capacitor 70 includes a lower capacitor electrode 71 as a pixel potential side capacitor electrode connected to the high concentration drain region 1e and the pixel electrode 9a and a part of the upper capacitor electrode 300 as a fixed potential side capacitor electrode. It is formed by being opposed to each other through the film 75.

  As shown in FIGS. 4 and 5, the upper capacitor electrode 300 is provided on the upper side of the TFT 30 as an upper light shielding film (built-in light shielding film) containing, for example, a metal or an alloy. The upper capacitor electrode 300 also functions as a fixed potential side capacitor electrode. The upper capacitor electrode 300 is, for example, at least one of metals such as Ti (titanium), Cr (chromium), W (tungsten), Ta (tantalum), Mo (molybdenum), Pd (palladium), and Al (aluminum). A single metal, an alloy, a metal silicide, a polysilicide, and a laminate of these. The upper capacitor electrode 300 may have a multilayer structure in which a first film made of, for example, a conductive polysilicon film and a second film made of a metal silicide film containing a refractory metal or the like are stacked.

  The lower capacitor electrode 71 is made of, for example, a conductive polysilicon film or a simple metal, an alloy, a metal silicide, including at least one of metals such as Ti, Cr, W, Ta, Mo, Pd, and Al. It consists of polysilicide, a laminate of these, etc., and functions as a pixel potential side capacitor electrode. The lower capacitor electrode 71 functions as a pixel potential side capacitor electrode, and functions as another example of a light absorption layer or an upper light shielding film disposed between the upper capacitor electrode 300 as the upper light shielding film and the TFT 30. Furthermore, the pixel electrode 9a and the high-concentration drain region 1e of the TFT 30 have a function of relay connection. However, the lower capacitive electrode 71 may also be composed of a single layer film or a multilayer film containing a metal or an alloy, like the upper capacitive electrode 300.

  The dielectric film 75 disposed between the lower capacitor electrode 71 and the upper capacitor electrode 300 as a capacitor electrode is, for example, a silicon oxide film such as an HTO (High Temperature Oxide) film, an LTO (Low Temperature Oxide) film, or a nitride. It is composed of a silicon film or the like.

  The upper capacitor electrode 300 extends from the image display region 10a where the pixel electrode 9a is disposed to the periphery thereof, and is electrically connected to a constant potential source to be a fixed potential.

  The lower light-shielding film 11a provided in a grid pattern below the TFT 30 via the base insulating film 12 shields the channel region 1a ′ of the TFT 30 and its surroundings from the return light that enters the device from the TFT array substrate 10 side. To do. Similarly to the upper capacitor electrode 300, the lower light-shielding film 11a includes, for example, a simple metal, an alloy, a metal silicide, including at least one of refractory metals such as Ti, Cr, W, Ta, Mo, and Pd. It is made of polysilicide or a laminate of these.

  In addition to the function of interlayer insulating the TFT 30 from the lower light-shielding film 11a, the base insulating layer 12 is formed on the entire surface of the TFT array substrate 10, thereby remaining rough after polishing the surface of the TFT array substrate 10 or after cleaning. It has a function of preventing deterioration of the characteristics of the pixel switching TFT 30 due to dirt or the like. The pixel electrode 9a is electrically connected to the high concentration drain region 1e in the semiconductor layer 1a through the contact holes 83 and 85 by relaying the lower capacitor electrode 71.

  As shown in FIGS. 4 and 5, the liquid crystal device 1 includes a transparent TFT array substrate 10 and a transparent counter substrate 20 disposed to face the TFT array substrate 10. The TFT array substrate 10 is made of, for example, a quartz substrate, a glass substrate, or a silicon substrate, and the counter substrate 20 is made of, for example, a glass substrate or a quartz substrate. An insulating film 20a as a planarizing film is formed on the lower surface of the counter substrate 20 in the figure.

  A pixel electrode 9a is provided on the TFT array substrate 10, and 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. For example, the pixel electrode 9a is made of a transparent conductive film such as an ITO (Indium Tin Oxide) film, and the alignment film 16 is made of an organic film such as a polyimide film.

  A counter electrode 21 is provided on the entire surface of the counter substrate 20, and an alignment film 22 subjected to a predetermined alignment process such as a rubbing process is provided below the counter electrode 21. The counter electrode 21 is made of a transparent conductive film such as an ITO film. The alignment film 22 is made of an organic film such as a polyimide film.

  As shown in FIG. 6, the counter substrate 20 is provided with a black matrix 153 as a lattice-shaped or striped light-shielding film. By adopting such a configuration, together with the upper light-shielding film provided as the upper capacitor electrode 300, it is possible to more reliably prevent light from being irradiated from the upper side in the figure to the channel region 1a ′ or its periphery. .

  A liquid crystal layer 50 is formed between the TFT array substrate 10 and the counter substrate 20 that are configured as described above and are arranged so that the pixel electrode 9a and the counter electrode 21 face each other. The liquid crystal layer 50 takes a predetermined alignment state by the alignment films 16 and 22 in a state where an electric field from the pixel electrode 9a is not applied.

  In FIG. 5, the pixel switching TFT 30 has an LDD (Lightly Doped Drain) structure, and includes a gate electrode 3a2, a channel region 1a ′ of the semiconductor layer 1a in which a channel is formed by an electric field from the scanning line 3a, and a scanning line. An insulating film 2 including a gate insulating film that insulates 3a from the semiconductor layer 1a, a low concentration source region 1b and a low concentration drain region 1c, a high concentration source region 1d, and a high concentration drain region 1e are provided. The low-concentration source region 1b, the low-concentration drain region 1c, the high-concentration source region 1d, and the high-concentration drain region 1e constitute an impurity region of the semiconductor layer 1a and are formed in mirror symmetry on both sides of the channel region 1a ′. Yes.

  The gate electrode 3a2 is composed of a conductive film such as a polysilicon film or a simple metal, an alloy, a metal silicide, a poly, including at least one of metals such as Ti, Cr, W, Ta, Mo, Pd, and Al. It is formed of silicide, a laminate of these, and the like, and is provided on the channel region 1a ′ via the insulating film 2 so as not to overlap the low concentration source region 1b and the low concentration drain region 1c. Therefore, in the TFT 30, the offset between the high concentration source region 1d and the high concentration drain region 1e and the gate electrode 3a2 is sufficiently secured.

  Note that the edge of the gate electrode 3a2 overlaps the boundary between the lightly doped source region 1b and the lightly doped drain region 1c and the channel region 1a ′ in plan view, and the lightly doped source region 1b and the lightly doped drain region 1c The parasitic capacitance generated between the gate electrode 3a2 and the gate electrode 3a2 is reduced. As a result, the TFT 30 transistor can operate at high speed, and the display performance of the liquid crystal device 1 is enhanced.

  In addition, in the liquid crystal device 1, the low-concentration source region 1 b and the low-concentration drain are effectively provided by the upper capacitor electrode 300 formed on the gate electrode 3 a 2 so as to cover the TFT 30 as compared with the case where the light is shielded only by the gate electrode 3 a 2. The region 1c can be shielded from light.

  As described above, according to the liquid crystal device 1, it is possible to reduce defects caused when displaying an image such as flicker using the TFT 30 with reduced light leakage current, and to display an image with high quality. In addition, since the TFT 30 has an LDD structure, the off-current flowing through the low-concentration source region 1b and the low-concentration drain region 1c is reduced when the TFT 30 is not operating, and the on-current flowing when the TFT 30 is operating is reduced. Is suppressed. Therefore, according to the liquid crystal device 1, it is possible to display an image with high quality by utilizing the advantage of the LDD structure and the fact that light leakage current hardly flows.

  On the lower light-shielding film 11a, a first interlayer insulating film 41 is formed in which a contact hole 81 leading to the high concentration source region 1d and a contact hole 83 leading to the high concentration drain region 1e are opened.

  A lower capacitor electrode 71 and an upper capacitor electrode 300 are formed on the first interlayer insulating film 41, and a second interlayer insulating film 42 in which contact holes 81 and 85 are respectively formed is formed thereon. ing.

  The second interlayer insulating film 42 is made of, for example, an acrylic resin film, and the upper surface is flattened through a fluidized state by heating. That is, a step is formed on the upper surface during the film formation due to the existence of the storage capacitor 70, the TFT 30, the scanning line 3a, and further the base light shielding film 11a on the lower layer side. The unevenness due to the steps is leveled.

  Further, a third interlayer insulating film 43 in which contact holes 85 are formed is formed of, for example, an acrylic resin film so as to cover the entire surface of the second interlayer insulating film 42 from above the data line 6a. The third interlayer insulating film 43 is an example of the “flattening film” in the present invention, and the pixel electrode 9 a and the alignment film 16 are formed on the flat upper surface.

  Next, the photodiode 150 will be described in detail with reference to FIGS. 4 and 6.

  As shown in FIGS. 4 and 6, the photodiode 150 is formed in a non-opening region that separates the opening regions of the plurality of pixels constituting the image display region 10 a on the TFT array substrate 10. The photodiode 150 detects the movement of an input unit such as a finger on the display surface 20S by detecting incident light that enters from the display surface 20S that is not facing the liquid crystal layer 50 of both surfaces of the counter substrate 20. The photodiode 150 is a PIN diode in which a lower electrode 150e, an N-type semiconductor layer 150d, a light receiving layer 150c, a P-type semiconductor layer 150b, and an upper electrode 150a are sequentially stacked from the TFT array substrate 10 side. The N-type semiconductor layer 150d, the light-receiving layer 150c, and the P-type semiconductor layer 150b constitute an example of the “photodiode body” in the present invention. According to the photodiode 150, a photocurrent is generated due to the light applied to the light receiving surface 150s, and the photocurrent is detected, whereby various information according to the movement of the input means such as a finger is displayed on the liquid crystal device. 1 can be entered.

  Here, the lower electrode 150 e is formed on the flat surface of the second interlayer insulating film 42 formed on the lower layer side of the third interlayer insulating film 43. The lower electrode 150e is formed in the same layer as the data line 6a which is an example of the “conductive layer” in the present invention. Such a lower electrode 150e is formed by a process common to the process of forming the data line. The upper electrode 150a is formed in the same layer as the pixel electrode 9a which is an example of the “conductive layer” of the present invention. Such an upper electrode 150a is formed by a process common to the process of forming the pixel electrode. Therefore, according to the upper electrode 150a and the lower electrode 150e, the manufacturing process of the liquid crystal device 1 is not complicated.

  The photodiode 150 is embedded in the third interlayer insulating film 43 so as to protrude from the third interlayer insulating film 43 toward the counter substrate 20. In the photodiode 150, the amount of the photodiode 150 embedded in the third interlayer insulating film 43 or the size of the photodiode 150 is adjusted, so that the third interlayer insulating film 43 of the photodiode 150 is transferred from the third interlayer insulating film 43 to the counter substrate 20. The size of the projecting portion, more specifically the height, is adjusted, and it is also used as a spacer that defines the inter-substrate gap between the TFT array substrate 10 and the counter substrate 20. Therefore, the photodiode 150 can accurately detect the movement or position of the input means such as a finger while accurately defining the inter-substrate gap.

  In addition, according to the photodiode 150, since it is not necessary to arrange a spacer in the opening region, the liquid crystal layer 50 is formed in the entire opening region. Therefore, according to the photodiode 150, it is possible to reduce the formation of a region that does not contribute to image display in a part of the opening region by arranging the spacer in the opening region. Further, since the photodiode 150 is also used as a spacer, it is not necessary to provide a spacer separately from the photodiode 150 only to maintain the inter-substrate gap.

  Since such a photodiode 150 has higher rigidity than a spacer made of resin or the like, for example, the height of each of the plurality of photodiodes 150 arranged on the TFT substrate 10 is set in advance. Therefore, the gap between the substrates can be made uniform as compared with the case where spacers made of resin or the like are arranged.

  Therefore, according to the liquid crystal device 1 according to this embodiment, the gap between the substrates can be defined by the photodiode 150 during the operation of the liquid crystal device 1, and the entire opening region is used as a region that contributes substantially to image display. Thus, it is possible to improve the aperture ratio which is lowered by arranging the spacer between the TFT array substrate 10 and the counter substrate 20. Therefore, according to the liquid crystal device 1, it is possible to improve the display quality of the image. In addition, according to the liquid crystal device 1 according to the present embodiment, since it is not necessary to provide a spacer separately from the photodiode 150, the material cost and the manufacturing cost of the liquid crystal device 1 can be reduced.

(Modification 1)
Next, a modification of the liquid crystal device according to the present embodiment will be described with reference to FIG. FIG. 7 is a diagram showing the configuration of the liquid crystal device according to this example, and is a cross-sectional view corresponding to FIG. In the following, common parts of the liquid crystal device 1 described above are denoted by common reference numerals, and detailed description thereof is omitted. In addition, the photodiode 151 included in the liquid crystal device according to the present example is disposed in a non-opening region on the TFT array substrate 10 when viewed in plan, similarly to the photodiode 150 described above.

  In FIG. 7, the photodiode 151 included in the liquid crystal device according to this example includes a lower electrode 151e, an N-type semiconductor layer 151d, a light-receiving layer 151c, and a P-type semiconductor layer 151b in this order from the lower side in the figure, which is the TFT array substrate 10 side. This is a PIN diode in which upper electrodes 151a are sequentially stacked. The lower electrode 151 e is formed on the third interlayer insulating film 43 and in the same layer as the pixel electrode 9 a electrically connected to the TFT 30. That is, in the liquid crystal device according to the present example, the pixel electrode 9a is an example of the “conductive layer” in the present invention. Therefore, according to the liquid crystal device according to this example, the lower electrode 151e can be formed by a process common to the pixel electrode 9a, and the manufacturing process of the liquid crystal device can be prevented from becoming complicated. In addition, the inter-substrate gap can be accurately defined by adjusting the size of the photodiode 151s on the third interlayer insulating film 43.

  The upper electrode 151 a is formed in the same layer as the counter electrode 21 formed on the surface facing the liquid crystal layer 50 of both surfaces of the counter substrate 20.

  In the photodiode 151, when the TFT array substrate 10 and the counter substrate 20 are bonded to each other, the upper electrode 151 a formed in advance on the counter substrate 20 side is formed on the upper surface of the P-type semiconductor layer 151 b included in the main body of the photodiode 151. It is formed by touching. Therefore, not only the lower electrode 151e and the main body of the photodiode 151 are set so as to define a target inter-substrate gap, but also the film thickness adjustment of the upper electrode 151a and the attachment of the TFT array substrate 10 and the counter substrate 20 are performed. The gap between the substrates can be finely adjusted by adjusting the alignment.

  In addition, since the upper electrode 151a is located immediately below the color filter 120 provided on the counter substrate 20, the light reflected by the input means such as a finger on the display surface 20s or the external light not blocked by the input means Is directly irradiated to the light receiving surface 151s of the photodiode 151 without being absorbed by the liquid crystal. Therefore, according to the photodiode 151, various information can be accurately input to the liquid crystal device from the input means without being affected by light absorption by the liquid crystal.

(Modification 2)
Next, another modification of the liquid crystal device according to the present embodiment will be described with reference to FIGS. FIG. 8 is a plan view showing the configuration of the pixel portion of the liquid crystal device according to this example, and FIG. 9 is a cross-sectional view taken along the line IX-IX ′ of FIG. The liquid crystal device according to this example employs an FFS driving method in which a liquid crystal layer is driven by a lateral electric field.

  8 and 9, the liquid crystal device according to this example is electrically connected to the scanning line 3a, the data line 6a, the common electrode 121 as an example of the “conductive layer” of the invention, and a pixel switching TFT (not shown). The pixel electrode 19, the lower light-shielding film 11a extending in a lattice shape, and the photodiode 152 are provided. The common electrode 121 is a common electrode extending across the plurality of pixel portions 119, and a fixed potential is supplied during operation of the liquid crystal device of this example. The pixel electrode 19 is electrically connected to the pixel switching TFT (not shown) and the data line 6a via the relay wiring 31.

  9, in the liquid crystal device according to this example, the pixel electrode 19 and the common electrode 121 are formed in different layers on the TFT array substrate 10. More specifically, the common electrode 121 is formed on the lower layer side of the pixel electrode 19, and the alignment state of liquid crystal molecules is controlled by a lateral electric field generated between these electrodes.

  The photodiode 152 is formed in a non-opening region on the TFT array substrate 10 and defines an inter-substrate gap between the TFT array substrate 10 and the counter substrate 20 without narrowing the opening region in the pixel portion 119. The photodiode 152 is a PIN diode in which a lower electrode 152e, an N-type semiconductor layer 152d, a light receiving layer 152c, a P-type semiconductor layer 152b, and an upper electrode 152a are sequentially stacked from the TFT array substrate 10 side.

  The upper electrode 152a is a portion where the conductive layer 39, which is an example of the “conductive layer” of the present invention, is formed on the insulating film 44 together with the pixel electrode 19 and extends to the upper surface of the P-type semiconductor layer 152b. It is formed using a common process. Therefore, according to the liquid crystal device according to the present example, the photodiode 152 that is also used as a spacer can be formed without complicating the manufacturing process of the liquid crystal device. The liquid crystal device according to the present example is not limited to the case where a part of the conductive layer formed in the same layer as the pixel electrode 19 is used for the upper electrode 152a, but the reflection formed on the TFT array substrate 10. A part of the film can also be used as the upper electrode 152a. Although not shown, the vertical relationship between the common electrode 121 and the pixel electrode 19 may be reversed. In this case as well, the alignment state of the liquid crystal molecules is controlled by a lateral electric field generated between the electrodes. A part of the conductive layer formed in the same layer as the common electrode 121 can be used for the upper electrode 152a.

<2: Electronic equipment>
Next, an embodiment of an electronic apparatus including the above-described liquid crystal device will be described.

  FIG. 10 is a perspective view of a mobile personal computer to which the above-described liquid crystal device is applied. In FIG. 10, a computer 1200 includes a main body 1204 having a keyboard 1202 and a liquid crystal display unit 1206 including the above-described liquid crystal device. The liquid crystal display unit 1206 is configured by adding a backlight to the back surface of the liquid crystal panel 1005, has a touch panel function, and has high display quality due to a high aperture ratio.

  Next, an example in which the above-described liquid crystal device is applied to a mobile phone will be described. FIG. 11 is a perspective view of a mobile phone that is an example of the electronic apparatus of the present embodiment. In FIG. 11, a mobile phone 1300 includes a liquid crystal device 1005 that adopts a reflective display format and has a plurality of operation buttons 1302 and spacers arranged on a light receiving element in the same manner as the liquid crystal device described above. According to the cellular phone 1300, since the light receiving element that detects incident light according to the movement of the input means such as the finger is also used as the spacer, the liquid crystal device has a high aperture ratio, and high-quality image display is achieved. Is possible.

It is the top view which looked at the liquid crystal device concerning this embodiment from the counter substrate side. It is II-II 'sectional drawing of FIG. 4 is an equivalent circuit of various elements, wirings, and the like in a plurality of pixels formed in a matrix that forms a display region of the liquid crystal device according to the present embodiment. 4 is a plan view of a plurality of pixel groups adjacent to each other on a TFT array substrate on which data lines, scanning lines, pixel electrodes, and the like are formed in the liquid crystal device according to the present embodiment. It is VV 'sectional drawing of FIG. It is VI-VI 'sectional drawing of FIG. It is sectional drawing which showed the structure of an example of the liquid crystal device which concerns on this embodiment. It is the top view which showed the structure of the other example of the liquid crystal device which concerns on this embodiment. It is IX-IX 'sectional drawing of FIG. It is a perspective view of the computer which is an example of the electronic device which concerns on this embodiment. It is a perspective view of the mobile telephone which is an example of the electronic device which concerns on this embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Liquid crystal device, 6a ... Data line, 9a, 19 ... Pixel electrode, 10 ... TFT array substrate, 20 ... Counter substrate, 30 ... TFT, 43 ... 3rd Interlayer insulating film, 50 ... liquid crystal layer, 121 ... common electrode, 150, 151, 152 ... photodiode

Claims (9)

A substrate,
A counter substrate disposed on the substrate to face the substrate;
A liquid crystal layer sandwiched between the substrate and the counter substrate;
A light receiving element that is formed in a non-opening region that separates the opening regions of a plurality of pixels constituting the display region on the substrate, and that also serves as a spacer that defines a gap between the substrate and the counter substrate. A liquid crystal device comprising: The said light receiving element is a photodiode which has a photodiode main body, and the upper electrode and lower electrode formed so that each of the upper surface and lower surface of the said photodiode main body may be contact | connected. Liquid crystal device. A pixel switching element provided for each of the pixels on the substrate;
A conductive layer electrically connected to the pixel switching element,
The liquid crystal device according to claim 2, wherein at least one of the upper electrode and the lower electrode is formed in the same layer as the conductive layer on the substrate. The photodiode is embedded in the planarization film so as to protrude from the planarization film formed on the pixel switching element toward the counter substrate,
The liquid crystal device according to claim 3, wherein the lower electrode is formed on a lower layer side of the planarizing film. The lower electrode is formed on a planarizing film that covers the pixel switching element, and is formed in the same layer as the pixel electrode that is electrically connected to the pixel switching element. 3. The liquid crystal device according to 3. The lower electrode is formed in the same layer as a common electrode common to the plurality of pixels,
The conductive layer is formed together with the pixel electrode in a layer different from the common electrode on the substrate,
The upper electrode is a portion where the conductive layer extends to the upper surface,
The liquid crystal device according to claim 3, wherein the liquid crystal layer is driven by a lateral electric field generated between the common electrode and the pixel electrode. The lower electrode is formed in the same layer as a pixel electrode corresponding to each of the plurality of pixels.
The conductive layer is formed with a common electrode on a different layer from the pixel electrode on the substrate,
The upper electrode is a portion where the conductive layer extends to the upper surface,
The liquid crystal device according to claim 3, wherein the liquid crystal layer is driven by a lateral electric field generated between the common electrode and the pixel electrode. The liquid crystal device according to any one of claims 2 to 5, wherein the upper electrode is an electrode formed on a surface facing the liquid crystal layer among both surfaces of the counter substrate. An electronic apparatus comprising the liquid crystal device according to any one of claims 1 to 8.

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