JP2009122256A - Electro-optical device and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain simplification of a layered structure in an electro-optical device and enable high-quality display. <P>SOLUTION: The electro-optical device includes, on a substrate (10): scanning lines (11); data lines (6a) disposed in an overlay side of the scanning lines and intersecting the scanning lines; pixel electrodes (9a) disposed in an overlay side of the data lines and corresponding to the intersections of the data lines and scanning lines; capacitance electrodes (71) disposed in an underlay side of the pixel electrodes and opposing to the pixel electrodes through a capacitance insulating film (75); and a semiconductor layer (1a) disposed in an overlay side of the scanning lines and in an underlay side of the data lines and having a data line side source-drain region (1d) electrically connected to the data line, a pixel electrode side source-drain region (1e) electrically connected to the pixel electrode, and a channel region (1a') comprising the same layer as the data lines and disposed opposing to a gate electrode (3a) through a gate insulating film, the gate electrode electrically connected to the scanning line. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

  A liquid crystal device, which is an example of this type of electro-optical device, includes, for example, a thin film transistor (TFT) and the like, and in addition to this, various wirings and electrodes such as thin data lines and scanning lines are laminated. Has been configured.

  By adopting the laminated structure as described above, the liquid crystal device can display a high-definition image while being small. For example, Patent Document 1 discloses a technique for realizing a liquid crystal device with a laminated structure including eight conductive layers.

JP 2001-281684 A

  However, in the liquid crystal device having the laminated structure as described above, the configuration of the device becomes complicated due to an increase in the number of layers, leading to an increase in the complexity of the manufacturing process, an increase in the manufacturing period, and an increase in cost. There is a technical problem.

  The present invention has been made in view of, for example, the above-described problems. For example, the present invention is an electro-optical device such as a liquid crystal device driven by an active matrix method, which is configured with relatively few layers and has high quality. It is an object of the present invention to provide an electro-optical device that enables display and an electronic apparatus including the electro-optical device.

  In order to solve the above problems, an electro-optical device of the present invention is provided with a substrate, a scanning line provided on the substrate, a data line provided on an upper layer side of the scanning line and intersecting the scanning line, A pixel electrode provided for each pixel defined corresponding to the intersection of the data line and the scanning line on the upper layer side of the data line, and a capacitive insulating film on the pixel electrode on the lower layer side of the pixel electrode A capacitor electrode provided so as to be opposed to each other, a data line side source / drain region provided on an upper layer side of the scanning line and on a lower layer side of the data line, and electrically connected to the data line, and the pixel electrode An electrically connected pixel electrode side source / drain region and a channel formed of the same layer as the data line and arranged to face the gate electrode electrically connected to the scanning line through a gate insulating film Semiconductor with region Provided with a door.

  According to the electro-optical device of the present invention, the scanning line is provided so as to extend on the substrate, and the data is provided on the upper layer side of the scanning line so as to extend across the data line. Yes. That is, the data line and the scanning line are provided so as to cross each other.

  A pixel electrode is provided on the upper layer side of the data line. The pixel electrode is a transparent electrode made of a transparent conductive material such as ITO (Indium Tin Oxide), for example, and a plurality of pixel electrodes are provided in a matrix form in a region to be a display region on the substrate corresponding to the intersection of the data line and the scanning line. It is done. Further, a capacitor electrode is provided on the lower layer side of the pixel electrode so as to face the pixel electrode through a capacitor insulating film. The capacitor electrode is typically made of a transparent conductive material such as ITO, for example, like the pixel electrode. The capacitor electrode may be connected to the capacitor line, or a part of the capacitor line may be the capacitor electrode. The capacitor electrode is connected to a power supply or wiring having a predetermined potential via a capacitor line.

  In addition, a semiconductor layer is provided on the upper layer side of the scan line and on the lower layer side of the data line, the data line side source / drain region electrically connected to the data line, and the pixel electrode electrically connected to the pixel electrode A side source / drain region and a channel region which is made of the same layer as the data line and which is arranged to face the gate electrode connected to the scanning line through the gate insulating film. Here, the “same layer” according to the present invention means a layer or a film formed by the same film forming process. For example, the film thickness of the data line and the gate electrode may not be the same. . Note that “consisting of the same layer” does not mean that it is continuous as a single layer or film, but it also means that a layer part or film part of the same layer that is separated from each other is sufficient. .

  Since the gate electrode is formed of the same layer as the data line, the gate electrode and the data line can be formed in the same film formation process. Therefore, it is possible to prevent the manufacturing process from becoming long and complicated. Note that the gate electrode is electrically connected to the scanning line through, for example, a contact hole provided on the side of the semiconductor layer.

  In addition to the semiconductor layer described above, a thin film transistor is formed on the substrate on the lower layer side of the capacitor electrode from the gate electrode and the gate insulating film. Here, the thin film transistor may be constructed as an LDD type thin film transistor by further having an LDD (Lightly Doped Drain) region in the semiconductor layer. The thin film transistor is typically constructed as a top gate thin film transistor having a semiconductor layer and a gate electrode disposed on the upper layer side of the semiconductor layer with a gate insulating film facing the channel region. Is done.

  In the present invention, in particular, as described above, the electro-optical device is configured by the five conductive layers (that is, the scanning line, the semiconductor layer, the data line, the capacitor electrode, and the pixel electrode in order from the lower layer side). Note that an insulating film such as the above-described capacitive insulating film or gate insulating film is provided between the conductive layers. In addition to the conductive layer and the insulating film described above, other wirings, electrodes, or the like may be provided.

  With the configuration described above, the electro-optical device of the present invention can control the supply of image signals from, for example, data lines to the pixel electrodes during its operation, thereby enabling image display using a so-called active matrix method. The image signal is transmitted from the data line at a predetermined timing by turning on and off a thin film transistor made of a semiconductor layer electrically connected between the data line and the pixel electrode in accordance with the scanning signal supplied from the scanning line. It is supplied to the pixel electrode through the thin film transistor. That is, the thin film transistor performs switching control of the pixel electrode. Further, by providing the capacitor electrode, the voltage applied to the pixel electrode is prevented from being attenuated, and a high contrast display or the like is realized.

  Here, for example, the scanning line, the data line, and the semiconductor layer are transparent to the aperture region of each pixel corresponding to the pixel electrode (that is, light that actually contributes to display in each pixel when viewed in plan on the substrate). Or a non-opening region surrounding the region to be reflected). That is, these scanning lines, data lines, and semiconductor layers are arranged not in the opening area of each pixel but in the non-opening area so as not to hinder display. As described above, the capacitor electrode is typically made of a transparent conductive material, and even if it is disposed in the opening region, it does not hinder display.

  Further, particularly in the present invention, as described above, the semiconductor layer is provided on the lower layer side of the data line. In other words, the data line is provided on the upper layer side than the semiconductor layer. Therefore, the data line can be formed so as to include a relatively low resistance metal such as aluminum after the semiconductor layer is subjected to the high temperature treatment. Therefore, if the data line is provided on the lower layer side than the semiconductor layer and is formed of a refractory metal such as titanium or tungsten, the electrical resistance of the data line is easily increased. It can be reduced (that is, the resistance of the data line can be easily reduced). For this reason, by reducing the wiring width of the data line, it is possible to widen the opening area, that is, to improve the aperture ratio of each pixel (that is, the ratio of the opening area to the entire area in each pixel). That is, it is possible to increase the aperture ratio of each pixel. Further, by reducing the resistance of the data line, an image signal to be written to the pixel electrode can be sufficiently written to the pixel electrode through the data line within a predetermined period. Therefore, the contrast can be improved.

  As described above, according to the electro-optical device of the present invention, it is possible to display a high-definition image by a limited number of conductive layers. Therefore, it is possible to prevent an increase in the complexity of the manufacturing process such as formation of deep contact holes, an increase in manufacturing period, an increase in cost, and the like due to an increase in the conductive layer. Further, the data line can be formed so as to include a metal having a relatively low resistance such as aluminum, so that the aperture ratio of each pixel can be increased and the contrast can be improved.

  In one aspect of the electro-optical device of the present invention, the scanning line functions as a light-shielding film that shields light incident from the substrate side.

  According to this aspect, light incident from the substrate side is blocked by the scanning line provided on the substrate. Note that as the light-shielding film, a high melting point metal such as titanium or tungsten that can withstand high-temperature treatment of the semiconductor layer and has excellent conductivity is preferably used. Alternatively, in the case where low temperature treatment is sufficient for the semiconductor layer, not only the refractory metal but also aluminum or the like excellent in conductivity may be used.

  If the light incident from the substrate side is not shielded, the incident light may cause a light leakage current in the semiconductor layer, which may cause display defects.

  However, in the present invention, since the scanning line functions as a light shielding film, it is possible to suppress the occurrence of the above-described light leakage current without providing a separate light shielding film. That is, light shielding can be realized without complicating the apparatus configuration. Therefore, it is possible to prevent an increase in manufacturing period and cost.

  In another aspect of the electro-optical device according to the aspect of the invention, the data line and the gate electrode include a stacked film in which two or more films including a conductive polysilicon film and a metal film are stacked.

  According to this aspect, a manufacturing process for manufacturing a thin film transistor having a gate electrode made of a conductive polysilicon film, which is a traditional or conventional typical thin film transistor in this type of electro-optical device, is almost or completely left intact. By utilizing this, a thin film transistor can be formed. That is, design changes related to transistor characteristics (for example, threshold voltage) of the thin film transistor can be reduced. Since design changes can be reduced in this way, it is very advantageous in practice.

  Furthermore, the electrical connection between the data line and the thin film transistor can be realized by the contact between the conductive polysilicon film constituting the data line and the semiconductor layer constituting the thin film transistor. It is possible to improve the connection.

  In another aspect of the electro-optical device according to the aspect of the invention, the capacitor electrode functions as a shield layer that prevents coupling between the pixel electrode and a lower layer side of the capacitor electrode.

  According to this aspect, since the capacitor electrode is provided on the lower layer side than the pixel electrode, the coupling between the pixel electrode and the lower layer side of the capacitor electrode (that is, the electrical or electromagnetic coupling such as the capacitive coupling) is performed. It functions as a shield layer for preventing (ring), that is, a conductive layer for electromagnetic shielding. The “lower layer side of the capacitor electrode” is, for example, the above-described data line, scanning line, semiconductor layer, and the like. Moreover, when another conductive layer exists, those layers may be sufficient.

  By preventing the coupling, it is possible to reduce the possibility of potential fluctuation or the like in the pixel electrode. Therefore, it is possible to display a higher quality image.

  In another aspect of the electro-optical device of the present invention, the electro-optical device is formed of the same layer as the semiconductor layer, the data line is a first data line, and the first data line extends in the extending direction. A second data line that runs parallel to the data line and is electrically connected to the first data line is provided.

  According to this aspect, since the first and second data lines are double wired, the electrical resistance of the data lines can be lowered as a whole. In addition, even if a failure such as disconnection occurs in one of the first and second data lines, since the other can function redundantly, the reliability of the electro-optical device can be improved.

  In the aspect including the second data line described above, the first and second data lines are opened in an interlayer insulating film provided between the first and second data lines in the stacked structure on the substrate. The contact holes may be electrically connected to each other through the contact holes.

  In this case, the first and second data lines can be easily and reliably electrically connected to each other through the contact hole.

  In the aspect including the second data line described above, the first and second data lines may be configured to overlap each other and to be in contact with each other so as to be electrically connected to each other.

  In this case, for example, an insulating film or the like is not provided between the first and second data lines in the stacked structure on the substrate, and the first and second data lines are formed so as to overlap and contact each other. The In other words, the data line is formed as a wiring having a two-layer structure in which the second data and the first data line are sequentially stacked from the lower layer side. Thus, for example, the first and second data lines are electrically connected to each other through a contact hole formed in an insulating film provided between the first and second data lines on the substrate. Compared to the case, the electrical resistance between the first and second data lines can be reliably reduced.

  In another aspect of the electro-optical device of the present invention, the electro-optical device further includes a counter substrate that is disposed to face the side where the pixel electrode is formed and sandwiches an electro-optical material between the substrate and the substrate.

  According to this aspect, the counter substrate is disposed on the side of the substrate where the pixel electrode is formed, and the electro-optical material is sandwiched between the substrate and the counter substrate. The electro-optic material can be controlled by applying a voltage from the pixel electrode. Therefore, for example, by applying a vertical electric field or a horizontal electric field between the pair of substrates, it is possible to display an image by allowing light to enter while controlling the electro-optical material.

  According to the electronic apparatus of the present invention, since the above-described electro-optical device according to the present invention is provided, it is possible to perform high-quality display while preventing an increase in the manufacturing period and an increase in cost. Various electronic devices such as a projection display device, a television, a cellular phone, an electronic notebook, a word processor, a viewfinder type or a monitor direct-view type video tape recorder, a workstation, a video phone, a POS terminal, and a touch panel can be realized. Further, as the electronic apparatus of the present invention, for example, an electrophoretic device such as electronic paper can be realized.

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

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

<First Embodiment>
The liquid crystal device according to the first embodiment will be described with reference to FIGS.

  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 schematic plan view showing a configuration of a liquid crystal device as seen from the side of a counter substrate, together with each component formed on the TFT array substrate, and FIG. 'Cross section.

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

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

  A light-shielding frame light-shielding film 53 that defines the frame 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.

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

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

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

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

  In FIG. 2, on the TFT array substrate 10, a laminated structure is formed in which wirings such as TFTs for pixel switching, scanning lines, and data lines are formed. In the image display area 10a, pixel electrodes 9a are provided in a matrix on the upper layer of wiring such as pixel switching TFTs, scanning lines, and data lines. An alignment film 16 is formed on the pixel electrode 9a.

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

  The liquid crystal layer 50 is made of, for example, a liquid crystal mixed with one or several types of nematic liquid crystals as an example of the “electro-optical material” according to the present invention, and takes a predetermined alignment state between the pair of alignment films. A liquid crystal storage capacitor is formed between the pixel electrode 9 a and the counter electrode 21 by applying a voltage to each of the liquid crystal devices during driving.

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

  Next, an electrical configuration of the pixel portion of the liquid crystal device according to the present embodiment will be described with reference to FIG.

  FIG. 3 is an equivalent circuit diagram of various elements, wirings, and the like in a plurality of pixels formed in a matrix that forms the image display area of the liquid crystal device according to the present embodiment.

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

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

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

  In order to prevent the image signal held here from leaking, a storage capacitor 70 is added electrically in parallel with the liquid crystal capacitor formed between the pixel electrode 9a and the counter electrode 21 (see FIG. 2). ing. The storage capacitor 70 is a capacitive element that functions as a storage capacitor that temporarily holds the potential of each pixel electrode 9a in response to supply of an image signal. According to the storage capacitor 70, the potential holding characteristic in the pixel electrode 9a is improved, and display characteristics such as contrast improvement and flicker reduction can be improved. A specific configuration of the storage capacitor 70 will be described in detail later.

  Next, a specific configuration of the pixel portion of the liquid crystal device according to the present embodiment will be described with reference to FIGS.

  FIG. 4 is a plan view of the pixel portion of the liquid crystal device according to the first embodiment. FIG. 5 is a cross-sectional view taken along line A-A ′ of FIG. 4. In FIGS. 4 and 5, the scale of each layer / member is different for each layer / member to have a size that can be recognized on the drawing. 4 and 5, for convenience of explanation, illustration of a portion located above the pixel electrode 9a is omitted. In FIG. 4, some wirings and electrodes such as the scanning lines 11 are transparently illustrated.

  In FIG. 4, a plurality of pixel electrodes 9a are provided in a matrix on the TFT array substrate 10 (see FIG. 2), and are transparent electrodes made of a transparent conductive material such as ITO, for example. Data lines 6a and scanning lines 11 are provided along the vertical and horizontal boundaries of the pixel electrode 9a. In other words, the scanning line 11 extends along the X direction, and the data line 6 a extends along the Y direction so as to intersect the scanning line 11. On the upper layer side of the scanning line 11, a pixel switching TFT 30 is provided for each pixel electrode 9a.

  The scanning line 11, the data line 6a, the TFT 30, and the relay electrode 60 to be described later are viewed on the TFT array substrate 10 in plan view, and the opening area of each pixel corresponding to the pixel electrode 9a (that is, each pixel is actually displayed. Is disposed in a non-opening region surrounding a region where light contributing to the light is transmitted or reflected. That is, the scanning line 11, the data line 6a, the TFT 30, and the relay electrode 60 are arranged not in the opening area of each pixel but in the non-opening area so as not to disturb display.

  During the operation of the liquid crystal device according to the present embodiment, the supply of the image signal from the data line 6a to the pixel electrode 9a is controlled, and the so-called active matrix image display is possible. The image signal is data at a predetermined timing when the TFT 30 which is a switching element electrically connected between the data line 6a and the pixel electrode 9a is turned on / off according to the scanning signal supplied from the scanning line 11. The pixel electrode 9a is supplied from the line 6a through the TFT 30.

  As shown in FIG. 5, on the TFT array substrate 10, various components such as the pixel electrode 9a described above have a laminated structure. The various components are, in order from the bottom, the first layer (that is, the first conductive layer) including the scanning line 11 and the like, the second layer (that is, the second conductive layer) including the semiconductor layer 1a, and the data line 6a. Etc., a third layer (ie, a third conductive layer), a fourth layer (ie, a fourth conductive layer) containing the capacitor electrode 71, etc., and a fifth layer (fifth conductive layer) containing the pixel electrode 9a, etc. ). Further, the base insulating film 12 is provided between the first conductive layer and the second conductive layer, and the first interlayer insulating film 41, the third conductive layer, and the fourth conductive layer are provided between the second conductive layer and the third conductive layer. Between the layers, a second interlayer insulating film 42, a capacitive insulating film 75 is provided between the fourth conductive layer and the fifth conductive layer, respectively, to prevent a short circuit between various components. The first interlayer insulating film 41 and the second interlayer insulating film 42 are made of, for example, NSG (non-silicate glass). In addition, the first interlayer insulating film 41 and the second interlayer insulating film 42 may be formed of 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.

  4 and 5, the TFT 30 includes the semiconductor layer 1a and the gate electrode 3a.

  The semiconductor layer 1a is made of polysilicon and has a channel region 1a ′, a data line side LDD region 1b, a pixel electrode side LDD region 1c, a data line side source / drain region 1d, and a pixel electrode side source / drain provided along the X direction. It consists of area 1e. That is, the TFT 30 has an LDD structure. The data line side source / drain region 1 d is electrically connected to the data line 6 a through a contact hole 81 formed in the first interlayer insulating film 41. The pixel electrode side source / drain region 1e is electrically connected to the pixel electrode 9a through a contact hole 83 formed in the first interlayer insulating film 41, a relay electrode 60 and a contact hole 85 described later.

  The data line side source / drain region 1d and the pixel electrode side source / drain region 1e are formed substantially in mirror symmetry along the X direction with respect to the channel region 1a '. The data line side LDD region 1b is formed between the channel region 1a 'and the data line side source / drain region 1d. The pixel electrode side LDD region 1c is formed between the channel region 1a 'and the pixel electrode side source / drain region 1e. The data line side LDD region 1b, the pixel electrode side LDD region 1c, the data line side source / drain region 1d, and the pixel electrode side source / drain region 1e are formed by implanting impurities into the semiconductor layer 1a by, for example, ion implantation. This is an impurity region. The data line side LDD region 1b and the pixel electrode side LDD region 1c are formed as low concentration impurity regions with less impurities than the data line side source / drain region 1d and the pixel electrode side source / drain region 1e, respectively. According to such an impurity region, when the TFT 30 is not operating, the off-current flowing between the source region and the drain region can be reduced, and a decrease in the on-current flowing when the TFT 30 is operating can be suppressed. The TFT 30 preferably has an LDD structure. However, the TFT 30 may have an offset structure in which no impurity implantation is performed in the data line side LDD region 1b and the pixel electrode side LDD region 1c. A self-alignment type in which the data line side source / drain region and the pixel electrode side source / drain region are formed by implanting the concentration may be used.

  4 and 5, the gate electrode 3a is disposed on the upper layer side of the semiconductor layer 1a via the first interlayer insulating film 41, and is formed to face the channel region 1a '. The first interlayer insulating film 41 is formed over almost the entire surface of the TFT array substrate 10. A portion of the first interlayer insulating film 41 formed between the channel region 1a ′ and the gate electrode in the stacked structure on the TFT array substrate 10 serves as a gate insulating film that insulates between the gate electrode 3a and the channel region 1a ′. Function.

  Particularly in this embodiment, as shown in FIG. 5, the gate electrode 3a is formed as a film having a two-layer structure of a layer 3a1 made of conductive polysilicon in the lower layer and a layer 3a2 containing aluminum in the upper layer. Therefore, a TFT 30 having a gate electrode made of a conductive polysilicon film, which is a traditional or conventional typical TFT in this type of liquid crystal device, is used almost or completely as it is. Can be formed. That is, design changes related to TFT characteristics (for example, threshold voltage) can be reduced. Since design changes can be reduced in this way, it is very advantageous in practice.

  The layer 3a2 containing aluminum may be formed of only an aluminum film. For example, a titanium (Ti) film, a titanium nitride (TiN) film, an aluminum (Al) film, and a titanium nitride (TiN) film may be used. You may form from the multilayer film laminated | stacked from the lower layer side in order. In other words, the gate electrode 3a may be formed by laminating a conductive polysilicon film and an aluminum film in this order from the lower layer side. For example, a conductive polysilicon film, a Ti film, a TiN film The Al film and the TiN film may be formed by laminating from the lower layer side in this order.

  In FIG. 5, a scanning line 11 is provided on the lower layer side of the semiconductor layer 1 a on the TFT array substrate 10 through the base insulating film 12. The scanning line 11 is made of a light-shielding conductive material such as a refractory metal material such as tungsten (W), Ti, or TiN. The scanning line 11 is formed so as to extend along the X direction of FIG. 4 and to include a region facing the channel region 1a 'and the pixel electrode side LDD region 1c of the TFT 30.

  According to such a scanning line 11, the TFT 30 receives the return light such as the back surface reflection on the TFT array substrate 10 or the light emitted from another liquid crystal device by a multi-plate projector or the like and penetrating the composite optical system. The channel region 1a ′ and the pixel electrode side LDD region 1c can be shielded almost or completely. That is, the scanning line 11 can also function as a light-shielding film that shields light incident from the TFT array substrate 10 side, in addition to the function as a scanning line that supplies the scanning signal Gi to the TFT 30. Furthermore, according to such a scanning line 11, it is possible to perform a high temperature process after the scanning line 11 is formed. That is, for example, when forming the semiconductor layer 1a constituting a part of the TFT 30 as the second layer, the semiconductor layer 1a is formed by a process performed in a relatively high temperature environment such as a low pressure CVD (Chemical Vapor Deposition) method. Is possible.

  In FIG. 5, the base insulating film 12 is made of, for example, a silicon oxide film. In addition to the function of insulating the semiconductor layer 1a from the scanning line 11, the base insulating film 12 is formed on the entire surface of the TFT array substrate 10, so that the surface of the TFT array substrate 10 is roughened during polishing or remains after cleaning. It has a function of preventing deterioration of the characteristics of the TFT 30 due to dirt or the like.

  In FIG. 5, a data line 6a and a relay electrode 60 are provided on the upper layer side of the semiconductor layer 1a on the TFT array substrate 10 via the first interlayer insulating film 41, in addition to the gate electrode 3a described above. .

  The data line 6a is made of the same layer as the gate electrode 3a (and the relay layer 60). That is, similarly to the gate electrode 3a, the data line 6a is formed as a film having a two-layer structure of a layer 6a1 made of conductive polysilicon in the lower layer and a layer 6a2 containing aluminum in the upper layer. The data line 6a is formed to extend along the Y direction in FIG. The data line 6 a is electrically connected to the data line side source / drain region 1 d of the TFT 30 through a contact hole 81 opened in the first interlayer insulating film 41. Since the contact hole 81 penetrates only one layer of the interlayer insulating film (that is, the first interlayer insulating film 41), the depth thereof can be relatively short, and the opening is easy by etching or the like. Also, since the aspect ratio is small, it is easy to make a good contact even at the bottom. Further, the electrical connection between the data line 6a and the data line side source / drain region 1d of the TFT 30 is made by connecting the layer 6a1 made of conductive polysilicon constituting the data line 6a and the data line side source / drain region made of polysilicon. This is realized by contact with 6a1, and the electrical connection between them can be improved.

  Here, in the present embodiment, in particular, as described above, the data line 6a is provided on the upper layer side of the semiconductor layer 1a, and is formed as a film containing aluminum. In other words, since the data line 6a is provided above the semiconductor layer 1a, the data line 6a is formed after the semiconductor layer 1a is formed by a process performed in a relatively high temperature environment such as a low pressure CVD method. For example, it can be formed to include a metal film having a relatively low melting point and a relatively low melting point such as aluminum. Therefore, if the data line 6a is provided on the lower layer side than the semiconductor layer 1a and is formed of a refractory metal such as titanium or tungsten, the data line 6a can be easily reduced in resistance. Can be For this reason, it is possible to improve the aperture ratio of each pixel by narrowing the wiring width of the data line 6a. Further, by reducing the resistance of the data line 6a, an image signal to be written to the pixel electrode 9a via the data line 6a within a predetermined period (that is, a fixed period in which the TFT 30 is turned on based on the scanning signal Gi). Si can be sufficiently written into the pixel electrode 9a. Therefore, the contrast can be improved.

  The relay electrode 60 is made of the same layer as the gate electrode 3a (and the data line 6a). That is, like the gate electrode 3a, the relay electrode 60 is formed as a film having a two-layer structure of a layer 61 made of conductive polysilicon in the lower layer and a layer 62 containing aluminum in the upper layer. The relay electrode 60 is electrically connected to the pixel electrode side source / drain region 1e of the TFT 30 through a contact hole 83 formed in the first interlayer insulating film 41, and the second interlayer insulating film 42 and the capacitor insulating film. The pixel electrode 9a is electrically connected through a contact hole 85 opened through 75. Therefore, the relay electrode 60 relays the electrical connection between the pixel electrode 9a and the pixel electrode side source / drain region 1e of the TFT 30. Therefore, it is possible to avoid a situation in which the interlayer distance between the relay electrode 60 and the pixel electrode side source / drain region 1e is long and it is difficult to connect the two using a single contact hole. Further, the relay electrode 60 makes it possible to reduce the electrical resistance between the pixel electrode 9a and the pixel electrode side source / drain region 1e.

  As shown in FIGS. 4 and 5, the gate electrode 3a, the data line 6a, and the relay electrode 60 are formed so as to have a planar shape that is continuous with each other when viewed in plan on the TFT array substrate 10. Instead, each person is formed so as to be divided for patterning. Accordingly, the gate electrode 3a, the data line 6a, and the relay electrode 60 are electrically insulated from each other by the second interlayer insulating film 42. Thus, the gate electrode 3a, the data line 6a, and the relay electrode 60 are formed from the same layer, thereby simplifying the configuration of the pixel and manufacturing the pixel as compared with the case where they are formed separately from different materials. The number of steps in the process can also be reduced and simplified.

  In FIG. 5, a capacitor electrode 71 is provided on the upper layer side of the data line 6 a on the TFT array substrate 10 via the second interlayer insulating film 42. The capacitor electrode 71 is provided so as to cover both the opening region and the non-opening region except for a portion where the contact hole 85 for electrically connecting the pixel electrode 9a and the relay electrode 60 is provided.

  The capacitor electrode 71 is disposed so as to face the pixel electrode 9 a with the capacitor insulating film 75 therebetween, and forms a storage capacitor 70.

  The capacitive electrode 71 is a fixed potential side capacitive electrode that is electrically connected to a constant potential source through a capacitive line, for example, and maintained at a fixed potential. The capacitor electrode 71 is made of a transparent conductive material such as ITO.

  The capacitor insulating film 75 is, for example, a single layer structure or a multilayer structure formed of a silicon oxide (SiO 2) film such as an HTO (High Temperature Oxide) film, an LTO (Low Temperature Oxide) film, or a silicon nitride (SiN) film. have.

  As described above, by forming the storage capacitor 70, the potential holding characteristic of the pixel electrode 9a is improved, and it is possible to improve display characteristics such as improvement of contrast and reduction of flicker. In this embodiment, in particular, since the storage capacitor 70 is formed by the pixel electrode 9a and the capacitor electrode 71, for example, compared with the case where the storage capacitor is formed by providing an upper electrode and a lower electrode in addition to the pixel electrode 9a. Thus, the device configuration can be simplified.

  Furthermore, in particular, in the present embodiment, since the capacitor electrode 71 is provided on the lower layer side than the pixel electrode 9a, the electrical or electromagnetic connection between the pixel electrode 9a and the lower layer side of the capacitor electrode 71 (for example, the data line 6a). It can also function as a shield layer that prevents typical coupling. Therefore, it is possible to reduce the possibility of potential fluctuations or the like in the pixel electrode 9a. Therefore, it is possible to display a higher quality image.

  The configuration of the pixel portion described above is common to each pixel portion as shown in FIG. Such pixel portions are periodically formed in the image display area 10a (see FIG. 1).

  With the configuration as described above, the liquid crystal device according to the present embodiment can display a high-quality image during its operation. Further, since it can be constituted by a relatively small number of conductive layers (that is, the first to fifth conductive layers), it is possible to prevent the laminated structure of various wirings and electrodes from becoming complicated. Therefore, it is possible to prevent an increase in manufacturing period and cost. Further, the data line 6a can be formed so as to contain a relatively low resistance metal such as aluminum, and the aperture ratio of each pixel can be increased.

Second Embodiment
Next, a liquid crystal device according to a second embodiment will be described with reference to FIG.

  FIG. 6 is a plan view of the pixel portion of the liquid crystal device according to the second embodiment. In FIG. 6, the same reference numerals are given to the same components as the components according to the first embodiment shown in FIGS. 1 to 5, and description thereof will be omitted as appropriate.

  In FIG. 6, the liquid crystal device according to the second embodiment is different from the liquid crystal device according to the first embodiment described above in that the liquid crystal device according to the second embodiment further includes a data line 6b made of the same layer as the semiconductor layer 1a. The configuration is substantially the same as that of the liquid crystal device according to the first embodiment described above.

  In FIG. 6, the data line 6b is particularly provided in the present embodiment.

  The data line 6b is formed of the same layer as the semiconductor layer 1a, and is formed to run parallel to the data line 6a along the direction in which the data line 6a continuously extends from the semiconductor layer 1a (that is, the Y direction). Has been. The data line 6b is electrically connected to the data line 6a through a contact hole 89 opened in the first interlayer insulating film 41 (see FIG. 5). That is, in the present embodiment, the data line is formed as a double wiring composed of the data lines 6a and 6b. Therefore, the overall electrical resistance of the data lines 6a and 6b can be reduced. In addition, even if one of the data lines 6a and 6b has a problem such as disconnection, the other can function redundantly, so that the reliability of the liquid crystal device according to the present embodiment can be improved. Furthermore, since the data line 6b is formed from the same layer as the semiconductor layer 1a, it causes little or no increase in the length and complexity of the manufacturing process.

<Third Embodiment>
Next, a liquid crystal device according to a third embodiment will be described with reference to FIGS.

  FIG. 7 is a plan view of the pixel portion of the liquid crystal device according to the third embodiment, and FIG. 8 is a cross-sectional view taken along the line B-B ′ of FIG. 7. 7 and 8, the same reference numerals are given to the same components as those according to the first embodiment shown in FIGS. 1 to 5, and description thereof will be omitted as appropriate.

  7 and 8, the liquid crystal device according to the third embodiment further includes a data line 6c formed of the same layer as the semiconductor layer 1a, and a channel region 1a ′ instead of the first interlayer insulating film 41 described above. Unlike the liquid crystal device according to the first embodiment described above in that the gate insulating film 14 is formed so as to cover the island shape, the other points are substantially the same as those of the liquid crystal device according to the first embodiment described above. It is configured.

  7 and 8, in this embodiment, in particular, a data line 6c is provided.

  The data line 6c is formed of the same layer as the semiconductor layer 1a, and is formed to run parallel to the data line 6a along the direction in which the data line 6a continuously extends from the semiconductor layer 1a (that is, the Y direction). Has been. Further, the data lines 6a and 6c are electrically connected to each other by being formed so as to overlap each other and to contact each other. In the present embodiment, the gate insulating film 14 formed in an island shape so as to cover the channel region 1a ′ instead of the first interlayer insulating film 41 (see FIG. 5) in the first embodiment described above is formed on the TFT array substrate 10. It is not formed between the data lines 6a and 6c in the upper stacked structure.

  That is, in the present embodiment, the data line is formed as a wiring having a stacked structure in which the data lines 6a and 6c are sequentially stacked from the lower layer side. Therefore, for example, compared with the case where the data lines 6a and 6c are electrically connected to each other through a contact hole opened in an interlayer insulating film provided between the data lines 6a and 6c. The electrical resistance of the wires 6a and 6c can be reliably reduced. Furthermore, since the data line 6c is formed from the same layer as the semiconductor layer 1a, it causes little or no increase in the length and complexity of the manufacturing process.

  In the present embodiment, the relay electrode 60 and the pixel electrode side source / drain region 1e are electrically connected to each other by being formed so as to overlap each other and to be in contact with each other. Therefore, the electrical resistance between the relay electrode 60 and the pixel electrode side source / drain region 1e (in other words, between the pixel electrode 9a and the pixel electrode side source / drain region 1e) can be lowered.

<Electronic equipment>
Next, the case where the liquid crystal device which is the above-described electro-optical device is applied to various electronic devices will be described.

  FIG. 9 is a plan view showing a configuration example of the projector. Hereinafter, a projector using the liquid crystal device as a light valve will be described.

  As shown in FIG. 9, a projector 1100 includes a lamp unit 1102 made of a white light source such as a halogen lamp. The projection light emitted from the lamp unit 1102 is separated into three primary colors of RGB by four mirrors 1106 and two dichroic mirrors 1108 arranged in the light guide 1104, and serves as a light valve corresponding to each primary color. The light enters the liquid crystal panels 1110R, 1110B, and 1110G.

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

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

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

  In addition to the electronic device described with reference to FIG. 9, a mobile personal computer, a mobile phone, a liquid crystal television, a viewfinder type, a monitor direct-view type video tape recorder, a car navigation device, a pager, an electronic device Examples include a notebook, a calculator, a word processor, a workstation, a videophone, a POS terminal, and a device equipped with a touch panel. Needless to say, the present invention can be applied to these various electronic devices.

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

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

It is a top view which shows the whole structure of the liquid crystal device which concerns on 1st Embodiment. It is H-H 'sectional drawing of FIG. 3 is an equivalent circuit diagram of a plurality of pixel units of the liquid crystal device according to the first embodiment. FIG. It is a top view of the pixel part of the liquid crystal device concerning a 1st embodiment. FIG. 5 is a cross-sectional view taken along the line A-A ′ of FIG. 4. It is a top view of the pixel part of the liquid crystal device concerning a 2nd embodiment. It is a top view of the pixel part of the liquid crystal device concerning a 3rd embodiment. It is B-B 'sectional drawing 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.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1a ... Semiconductor layer, 1a '... Channel region, 1b ... Data line side LDD region, 1c ... Pixel electrode side LDD region, 1d ... Data line side source / drain region, 1e ... Pixel electrode side source / drain region, 3a ... Gate electrode, 6a, 6b, 6c ... data line, 9a ... pixel electrode, 10 ... TFT array substrate, 10a ... image display area, 11 ... scanning line, 12 ... base insulating film, 30 ... TFT, 71 ... capacitive electrode, 60 ... relay electrode 75 ... Capacitance insulating film

Claims (9)

A substrate,
A scanning line provided on the substrate;
A data line provided on an upper layer side of the scanning line and intersecting the scanning line;
A pixel electrode provided for each pixel defined corresponding to the intersection of the data line and the scanning line on the upper side of the data line;
A capacitor electrode provided on the lower layer side of the pixel electrode so as to face the pixel electrode through a capacitor insulating film;
A data line side source / drain region electrically connected to the data line and a pixel electrode side source / drain region provided on the upper side of the scanning line and on the lower side of the data line, and electrically connected to the data line And a semiconductor layer having a channel region which is formed of the same layer as the data line and which is disposed so as to face a gate electrode electrically connected to the scanning line through a gate insulating film. An electro-optical device.   The electro-optical device according to claim 1, wherein the scanning line functions as a light-shielding film that shields light incident from the substrate side.   3. The electro-optical device according to claim 1, wherein the data line and the gate electrode are formed of a laminated film in which two or more films including a conductive polysilicon film and a metal film are laminated.   4. The electro-optical device according to claim 1, wherein the capacitor electrode functions as a shield layer that prevents coupling between the pixel electrode and a lower layer side of the capacitor electrode. 5.   The first data line is formed of the same layer as the semiconductor layer, and the data line is parallel to the first data line along a direction in which the first data line extends. 5. The electro-optical device according to claim 1, further comprising a second data line electrically connected to the data line.   The first and second data lines are electrically connected to each other through a contact hole formed in an interlayer insulating film provided between the first and second data lines in the stacked structure on the substrate. The electro-optical device according to claim 5.   6. The electro-optical device according to claim 5, wherein the first and second data lines are electrically connected to each other by being formed so as to overlap and contact each other.   8. The apparatus according to claim 1, further comprising a counter substrate disposed opposite to the substrate electrode on which the pixel electrode is formed and sandwiching an electro-optical material between the substrate and the substrate. The electro-optical device according to 1.   An electronic apparatus comprising the electro-optical device according to claim 1.

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