JP2006126873A - Electro-optical device and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To display a high quality image on an optoelectronic device by preventing light beams incident on TFTs beforehand. <P>SOLUTION: Pixel electrodes, TFTs which include semiconductor layers (1a) connected to the electrodes, scanning lines (3a) connected to TFTs and data lines (6a) are provided on a TFT array substrate. The scanning lines include narrow width sections (3aa) which are opposed to channel regions (1a') in the semiconductor layers and act as gate electrodes and wide width sections (3ab) which are not opposed to the channel regions. The wide width sections are preferably constituted of light shielding material. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention belongs to the technical field of electro-optical devices and electronic devices, and in particular, on one of a pair of substrates formed by sandwiching an electro-optical material such as liquid crystal, a thin film transistor (hereinafter referred to as “thin film transistor”) It belongs to the technical field of an electro-optical device including a TFT and a so-called active matrix drive, and an electronic apparatus including such an electro-optical device.

  Conventionally, by providing pixel electrodes arranged in a matrix, TFTs connected to each of the electrodes, scanning lines and data lines connected to each of the TFTs and provided in parallel in the row and column directions, respectively. An electro-optical device capable of controlling the operation by supplying a scanning signal to a TFT through a scanning line and capable of so-called active matrix driving by supplying an image signal to the TFT and the pixel electrode through a data line is known. ing. In such an electro-optical device, a device that can display a higher quality image while being smaller in size has recently been generally demanded.

  In order to meet such demands, various problems must be overcome, but in particular, overcoming the problems related to light incidence on the TFT provided in each pixel, especially the channel region in the semiconductor layer. is important. This is because when the channel region is irradiated with light, a light leakage current is generated by excitation with the light, and the characteristics of the TFT change, causing flicker or the like on the image. In particular, when this electro-optical device capable of driving an active matrix is used as a light valve of a liquid crystal projector, the intensity of light incident on the light valve is high. It is more important to shield the light.

  Therefore, conventionally, a light-shielding film that defines the opening area of each pixel is provided on a counter substrate facing the TFT array substrate on which the TFT or the like is formed with an electro-optical material such as liquid crystal interposed therebetween. Thus, a configuration is adopted in which light does not reach the channel region and its peripheral region. Alternatively, on the TFT array substrate, a data line made of a metal film such as Al (aluminum) that passes over the TFT is used as a light shielding film. By adopting such a configuration, it is possible to prevent light from entering the TFT of the electro-optical device or its channel region, that is, to prevent generation of light leakage current.

  However, the above-described light shielding technique has the following problems. That is, according to the technology for forming the light shielding film on the counter substrate or the TFT array substrate, the space between the light shielding film and the channel region is viewed, for example, via a liquid crystal layer, an electrode, an interlayer insulating film, etc. It is quite far away, and it is not sufficient to shield light incident obliquely between them. In particular, in a small electro-optical device used as a light valve of a projector, incident light is a light beam obtained by converging light from a light source with a lens, so that an obliquely incident component cannot be ignored (for example, perpendicular to a substrate). In other words, it is a practical problem that the light is not sufficiently shielded against such oblique incident light.

  In particular, in order to meet the general request for downsizing of the electro-optical device described above, as the device becomes more precise or the pixel pitch becomes finer, an image that is brighter in line with the general request for higher display image quality. Therefore, the light intensity of the incident light tends to increase, and according to the conventional light shielding technique described above, it is more difficult to perform sufficient light shielding.

  The present invention has been made in view of the above problems, and an electro-optical device capable of displaying a high-quality image by preventing the incidence of light on the TFT, and such an electro-optical device. It is an object to provide an electronic device provided.

In order to solve the above problems, a first electro-optical device according to an aspect of the invention supplies a pixel electrode on a substrate, a thin film transistor that supplies an image signal to the pixel electrode by a switching operation, and supplies the image signal to the thin film transistor. A first wiring; and a second wiring for supplying a scanning signal for controlling the switching operation to the thin film transistor. The second wiring has a narrow width as a gate electrode facing the channel region of the thin film transistor. And a wide portion that is wider than the narrow portion and does not face the channel region.
The electro-optical device of the present invention includes a pixel electrode on a substrate,
A pixel transistor for supplying an image signal to the pixel electrode by a switching operation;
A first wiring for supplying the image signal to the pixel transistor, a second wiring for supplying a scanning signal for controlling the switching operation to the pixel transistor, and the first wiring and the pixel transistor. A light shielding film disposed between and overlapping the pixel transistor;
A narrow portion serving as a gate electrode facing the channel region of the pixel transistor and a wide portion wider than the narrow portion and not facing the channel region, and formed in the wide portion region. And an electrode portion electrically connected to the second wiring by a contact hole.

  According to the first electro-optical device of the present invention, it is possible to control ON / OFF of the thin film transistor by supplying a scanning signal to the thin film transistor through the second wiring, and further, when the thin film transistor is turned on. In this case, since an image signal can be supplied to the pixel electrode through the first wiring, so-called active matrix driving can be realized.

  In the present invention, in particular, the second wiring includes a narrow portion as a gate electrode facing the channel region of the thin film transistor, and a wide portion wider than the narrow portion and not facing the channel region. Contains. That is, the second wiring according to the present invention takes a form in which an umbrella is spread around the channel region. As a result, the progress of light entering the channel region of the thin film transistor is blocked by the wide portion of the second wiring according to the present invention. In particular, such a shielding effect is effectively exhibited with respect to light incident obliquely with respect to the channel region.

  Therefore, according to the present invention, it is possible to suppress the generation of light leakage current in the thin film transistor as much as possible, and thus it is possible to display a high-quality image free from flicker.

  In the present invention, “wide” means wider than the width of the “narrow part”, and “narrow” means narrower than the width of the “wide part”. Meaning. In short, the specific degree of wideness when referring to “wide part” and “narrow part” is determined by the relative relationship between the two.

  In this connection, the width value that the wide portion or the narrow portion should actually have depends on the strength of the light shielding effect, the maintenance of the pixel aperture ratio, or other components on the substrate. In consideration of circumstances such as layout, it can be appropriately determined by theory, empirical, experimental, simulation, or the like. More specifically, in the case where a lattice-shaped light shielding film that is typically formed is provided on a counter substrate that is opposed to the substrate with an electro-optic material interposed therebetween, the width of the wide portion is It may be formed so as not to exceed the width of the light shielding film. According to this, since the wide portion is confined in the non-opening region, the pixel aperture ratio is not affected.

  In addition, as described above, the “electro-optical material” in the present invention is typically a liquid crystal, but in addition, a powder EL (electroluminescence) dispersed in a suitable binder is also available. ), Or inorganic or organic EL, etc. may also be applicable. In this case, an electric field is applied to the EL, and the light is emitted by itself, so that an image is displayed. In such an “EL display device”, the TFT, Considering the case where the wiring, the first wiring, and the like are provided, the application of the present invention is naturally possible even in such a case.

  The second electro-optical device of the present invention includes a pixel electrode on a substrate, a thin film transistor that supplies an image signal to the pixel electrode by a switching operation, a first wiring that supplies the image signal to the thin film transistor, and the thin film transistor A second wiring for supplying a scanning signal for controlling the switching operation, a narrow portion as a gate electrode facing the channel region of the thin film transistor, and a width wider than the narrow portion, and the channel region And an electrode portion electrically connected to the second wiring.

  According to the second electro-optical device of the present invention, active matrix driving is possible in substantially the same manner as the first electro-optical device of the present invention described above. However, in the present invention, the scanning signal is supplied to the thin film transistor through the electrode portion in addition to the second wiring.

  And especially in this invention, while providing the electrode part containing a narrow part and a wide part, this electrode part becomes a form electrically connected with the 2nd wiring. As a result, for example, the second wiring and the electrode portion can be formed in another layer on the substrate, so that the layout flexibility of the arrangement mode such as the thin film transistor can be increased. The two wirings can be made of a material having a higher electrical conductivity, and the electrode part can be made of a material having a higher light shielding property.

  In any case, according to the second electro-optical device of the present invention, it is possible to realize light shielding for the channel region by the wide portion, as in the first electro-optical device of the present invention described above. It is still possible to suppress the occurrence of light leakage current and display a higher quality image.

  In one aspect of the second electro-optical device of the present invention, the electrode part and the second wiring are electrically connected through a contact hole.

  According to this aspect, the electrical connection between the second wiring and the electrode portion is performed via the contact hole, so that both elements are separated from each other on the substrate with, for example, one or more interlayer insulating films interposed therebetween. It can be formed as a layer, and the layout flexibility of various components on the substrate can be increased.

  In one aspect of the first electro-optical device of the present invention and another aspect of the second electro-optical device of the present invention, at least a part of the wide portion has a region overlapping the first wiring in plan view. Have.

  According to this aspect, for example, when a stacked structure of the channel region, the second wiring or electrode portion including the wide portion, and the first wiring is formed in order from the bottom, the stacked structure enters from above the first wiring. The incoming light is first shielded on the upper surface of the first wiring, and the light that has passed through the first wiring is shielded on the upper surface of the wide portion, so that a higher light shielding function is exhibited. In addition, the fact that the first wiring and the wide portion overlap in plan view means that the light entry path to the channel region is limited, and this also realizes a higher light shielding function. Will be.

  In another aspect of the first or second electro-optical device of the present invention, the wide portion includes a portion extending from the narrow portion.

  According to this aspect, the second wiring or the electrode portion having the wide portion and the narrow portion can be formed relatively easily. Specifically, for example, the second wiring or the electrode according to the present aspect is used by using known photolithography and etching on the premise that a pattern in which the wide portion and the narrow portion are so integrated is formed. The part can be easily formed.

  In another aspect of the first or second electro-optical device of the present invention, the wide portion includes a portion connected from the narrow portion.

  According to this aspect, for example, the wide part includes a part formed by connecting a separately prepared conductive member or the like to the narrow part. Even in such a case, the wide portion can be formed relatively easily.

  In this case, in particular, a material suitable for a narrow portion where a function as a gate electrode is expected, and a material suitable for a wide portion where high light shielding performance is expected are used. It is also possible to easily configure the narrow portion and the wide portion with different materials.

  Specifically, for example, the narrow portion is made of conductive polysilicon while the wide portion is shielded from light such as WSi (tungsten silicide) as described later. It can be composed of materials, etc. According to such a configuration, a light-shielding material that is generally not suitable for having a function as a gate electrode does not have such a function, and the polysilicon film has this function. At the same time, a high light shielding function can be achieved.

  In another aspect of the first or second electro-optical device of the present invention, the wide portion is made of a light shielding material.

  According to this aspect, since the wide portion is made of the light shielding material, the light shielding function by the wide portion is more reliably exhibited.

  In addition, in this aspect, you may comprise not only the wide part which consists of a light-shielding material but of course including a wide part and a narrow part, and comprising a light-shielding material. In the case of the former, as described above, it can be suitably realized in the above-described aspect including the portion in which the wide portion is connected from the narrow portion.

  In addition, specific examples of the “light-shielding material” referred to in this aspect include at least one of refractory metals such as Ti (titanium), Cr (chromium), W (tungsten), Ta (tantalum), and Mo (molybdenum). A single metal, an alloy, a metal silicide, a polysilicide, a laminate of these, and the like including one can be given.

  In another aspect of the first or second electro-optical device of the present invention, the second wiring or the electrode portion has a multilayer structure.

  According to this aspect, for example, the second wiring or the electrode portion has a two-layer structure including a layer for effectively functioning as a gate electrode and a layer for providing a light shielding performance (the former is, for example, poly Examples of the latter include refractory metals such as Ti, Cr, W, Ta, and Mo as described above.) In the present invention, the second can be used. The performance required for the wiring or the electrode part can be more preferably exhibited. Accordingly, it is possible to ensure a suitable operation of the thin film transistor or the electro-optical device and to exhibit a sufficient light shielding performance.

  In another aspect of the first or second electro-optical device of the present invention, the wide portion extends in one or both of the extending directions of the channel region as seen from the edge of the narrow portion. ing.

  According to this aspect, since the wide portion extends to one or both of the extending channel regions, the arrangement of the thin film transistor and the second wiring or the electrode portion can be adjusted appropriately. become. Here, the case where the wide portion is “extending to one side” means that one end portion of the wide portion is on a straight line along one end portion of the channel region in the extending direction of the channel region. However, the other ends do not run on a straight line parallel to the straight line, while the “extending in both” case means one end of the channel region and This is a case where neither one end of the wide portion nor the other end is on a straight line along each of the other ends.

  In this aspect, since it is possible to freely determine the portion to be “wide” with respect to the narrow portion, it is preferable to adjust the arrangement mode of the thin film transistor, the second wiring, and the electrode portion. In addition to this, it is possible to increase the degree of freedom of layout of various components on the substrate.

  In the above description, whether or not the wide part is specifically protruded with respect to the narrow part in either case where the wide part is extended only on one side or both sides is already described. As described above, it can be determined in consideration of various circumstances.

  In another aspect of the first or second electro-optical device of the present invention, the pixel electrodes are arranged in a matrix, and the channel regions are pixels adjacent to each other across the second wiring in a plan view. It is formed in an intersection region where a long first gap extending between the electrodes and a long second gap extending between the adjacent pixel electrodes across the first wiring intersect.

  According to this aspect, since the channel region of the thin film transistor is formed in the intersection region, a configuration in which light is most unlikely to be generated appears. Therefore, in combination with the function and effect of the wide portion according to the present invention, the electro-optical device according to this aspect can more reliably suppress the occurrence of light leakage current and display a higher quality image. It becomes possible.

  Note that “arranged in a matrix” as used in this embodiment includes a simple form in which the pixel electrodes are linearly arranged vertically and horizontally, for example, at least one of the longitudinal and lateral directions. It includes a form that is arranged in a meandering pattern or a staggered pattern only.

  In this aspect, in particular, the channel region, the source region, and the drain region are formed so as to extend along the second gap, and the width of the narrow portion extends along the second gap of the channel region. And the width of the wide portion has a value larger than the length.

  According to such a configuration, the thin film transistor is formed so that the direction of the so-called “channel length” (“the length of the channel region along the second gap” described above) coincides with the direction of the second gap. Will be. The width of the narrow portion coincides with the channel length, and the width of the wide portion has a width that is larger than the channel length.

  Such a structure can be said to reveal one of the most preferable arrangement modes of the thin film transistor or its channel region and the second wiring or the electrode portion, and based on this, the arrangement mode of the first wiring, the pixel electrode, and the like. This can be suitably determined.

  In another aspect of the first or second electro-optical device of the present invention, a lower light-shielding film is further provided below the thin film transistor.

  According to this aspect, it is possible to more reliably prevent light from entering the thin film transistor. That is, if the wide portion according to the present invention is provided on the upper side of the thin film transistor, it is possible to block light entering the channel region from the upper side and the lower side, and the wide portion is provided below the thin film transistor. If it is provided on the side, double light shielding is possible for the lower side.

  Specifically, for example, when the electro-optical device according to this aspect is used as a light valve in a projection display device capable of color display, the projection display device includes, for example, three colors of red, blue, and green. Three sets of light valves (electro-optical devices) corresponding to colors are provided to face a set of prisms. In such a case, for example, light that has passed through the electro-optical device corresponding to blue facing the electro-optical device corresponding to red may enter. This light becomes light incident from the lower side of the thin film transistor as so-called return light.

  Here, according to the lower light-shielding film according to the present aspect, light incident from the lower side of the thin film transistor can be shielded, so that the possibility of occurrence of light leakage current in the thin film transistor can be further reduced. It becomes possible.

  The electronic apparatus of the present invention comprises the above-described first or second electro-optical device of the present invention (including various aspects thereof).

  According to the electronic apparatus of the present invention, since the electro-optical device having an excellent light shielding property with respect to the thin film transistor is provided, a projection display device (liquid crystal projector) capable of displaying a high-quality image without flicker or the like. ), Various electronic devices such as a liquid crystal television, a mobile 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, a touch panel, and the like.

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

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the electro-optical device of the invention is applied to a liquid crystal device.

(First embodiment)
First, the configuration of the pixel portion of the electro-optical device according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an equivalent circuit of various elements, wirings, and the like in a plurality of pixels formed in a matrix that constitutes an image display region of the electro-optical device. 2 is a plan view of a plurality of adjacent pixel groups on the TFT array substrate on which data lines, scanning lines, pixel electrodes, and the like are formed, and FIG. 3 is a cross-sectional view taken along line AA ′ of FIG. is there. In FIG. 3, the scale of each layer / member is different for each layer / member so that each layer / member can be recognized on the drawing.

  In FIG. 1, each of a plurality of pixels formed in a matrix that forms an image display area of the electro-optical device according to the first embodiment includes a pixel electrode 9 a and a TFT 30 for switching control of the pixel electrode 9 a. The data line 6 a formed and supplied with an image signal 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.

  Further, the scanning line 3a is electrically connected to the gate of the TFT 30, and the scanning signals G1, G2,..., Gm are applied to the scanning line 3a in a pulse-sequential manner in this order at a predetermined timing. It is configured. The pixel electrode 9a is electrically connected to the drain of the TFT 30, and the image signal S1, S2,..., Sn supplied from the data line 6a is obtained by closing the switch of the TFT 30 as a switching element for a certain period. Write at a predetermined timing.

  Image signals S 1, S 2,..., Sn written in a liquid crystal as an example of an electro-optical material via the pixel electrode 9 a are held for a certain period with the counter electrode formed on the counter substrate. The liquid crystal modulates light and enables gradation display by changing the orientation and order of the molecular assembly depending on the applied voltage level. In the normally white mode, the transmittance for incident light is reduced according to the voltage applied in units of each pixel, and in the normally black mode, the light is incident according to the voltage applied in units of each pixel. The light transmittance is increased, and light having a contrast corresponding to the image signal is emitted from the electro-optical device as a whole.

  In order to prevent the image signal held here from leaking, a storage capacitor 70 is added in parallel with the liquid crystal capacitor formed between the pixel electrode 9a and the counter electrode. The storage capacitor 70 includes a capacitor line 300 that is provided side by side with the scanning line 3a and is fixed at a constant potential.

  Hereinafter, a more realistic configuration of the electro-optical device that realizes the above-described circuit operation using the data line 6a, the scanning line 3a, the TFT 30, and the like will be described with reference to FIGS.

  First, the electro-optical device according to the first embodiment includes a transparent TFT array substrate 10 and a transparent counter substrate 20 disposed to face the transparent TFT array substrate 10 as shown in FIG. And. 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.

  As shown in FIG. 3, the TFT array substrate 10 is provided with a pixel electrode 9a, and an alignment film 16 subjected to a predetermined alignment process such as a rubbing process is provided above the pixel electrode 9a. The pixel electrode 9a is made of a transparent conductive film such as an ITO (Indium Tin Oxide) film. On the other hand, a counter electrode 21 is provided over 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. Of these, the counter electrode 21 is also made of a transparent conductive film such as an ITO film, for example, in the same manner as the pixel electrode 9a. The alignment films 16 and 22 are made of a transparent organic film such as a polyimide film.

  On the other hand, in FIG. 2, a plurality of the pixel electrodes 9a are provided in a matrix on the TFT array substrate 10 (the outline is indicated by dotted line portions 9a ′), and the pixel electrodes 9a are respectively arranged at the vertical and horizontal boundaries. A data line 6a and a scanning line 3a are provided along the line. The data line 6a is along a gap between pixel electrodes 9a adjacent to each other in the x direction in FIG. 2, that is, a gap extending in the y direction in FIG. 2 (corresponding to a “second gap” in the present invention). The material is formed of a metal film such as an aluminum film or an alloy film. On the other hand, the scanning line 3a is a gap between pixel electrodes 9a adjacent to each other in the y direction in FIG. 2, that is, a gap extending in the x direction in the same figure (corresponding to the “first gap” in the present invention). Are formed along. Among these, the scanning line 3a is disposed so as to oppose the channel region 1a 'indicated by the hatched region rising to the right in the drawing in the semiconductor layer 1a, and a part of the scanning line 3a functions as a gate electrode. That is, the main line portion of the scanning line 3a is disposed opposite to the channel region 1a ′ as a gate electrode at the intersection of the scanning line 3a and the data line 6a (corresponding to the “intersection area” in the present invention). A pixel switching TFT 30 is provided.

  As shown in FIG. 3, the TFT 30 has an LDD (Lightly Doped Drain) structure, and, as described above, the scanning line 3a functioning as a gate electrode, for example, a polysilicon film is used as a constituent element. The channel region 1a ′ of the semiconductor layer 1a in which a channel is formed by the electric field from 3a, the insulating film 2 including the gate insulating film that insulates the scanning line 3a from the semiconductor layer 1a, the low-concentration source region 1b in the semiconductor layer 1a, and the low A concentration drain region 1c, a high concentration source region 1d, and a high concentration drain region 1e are provided.

  In particular, in the first embodiment, the scanning line 3a includes a narrow portion 3aa as a gate electrode facing the channel region 1a ′ of the TFT 30 and a wide portion 3ab not facing as shown in FIG. . The narrow portion 3aa and the wide portion 3ab are in a relationship of extending from each other. As a result, the scanning line 3a including the narrow portion 3aa and the wide portion 3ab can be formed all at once by using a photolithography method or the like.

  More specifically, as shown in FIG. 2, the width Wa of the narrow portion 3aa is the length of the channel region 1a ′ in the direction sandwiched between the drain regions 1c and 1e and the source regions 1b and 1d of the TFT 30, that is, The width Wb of the wide portion 3ab is determined so as to coincide with the channel length, so that the relationship of Wb> Wa is satisfied, and so as to protrude from both edges of the narrow portion 3aa (that is, 2 so as to protrude in both the + y direction and the −y direction).

  Further, as can be seen from FIG. 2, more specifically, the scanning line 3a has a narrow portion 3aa in the scanning line 3a so that the wide portion 3ab has a region overlapping the data line 6a in plan view. The boundary region between the wide portion 3ab and the wide portion 3ab is formed so as to overlap with the edge of the data line 6a in plan view. FIG. 2 shows that this overlapping region has a width Wp.

  The scanning line 3a including the narrow portion 3aa and the wide portion 3ab is made of a light shielding material in the first embodiment. Here, as the light-shielding material, for example, a metal simple substance, an alloy, a metal silicide, a polysilicide, or a laminate of these including at least one of refractory metals such as Ti, Cr, W, Ta, and Mo. Etc.

  In the above description, the TFT 30 has an LDD structure (see FIG. 3). However, the present invention is not limited to such a form. For example, the low concentration source region 1b and the low concentration drain region 1c may contain impurities. The gate electrode (that is, the narrow portion 3aa) formed of a part of the scanning line 3a is used as a mask to implant impurities at a high concentration, and the high concentration source region and the high concentration are self-aligned. A self-aligned TFT for forming a drain region may be used. Further, the semiconductor layer 1a constituting the TFT 30 may be a non-single crystal layer or a single crystal layer. A known method such as a bonding method can be used for forming the single crystal layer. By making the semiconductor layer 1a a single crystal layer, it is possible to improve the performance of peripheral circuits in particular.

  On the other hand, in FIG. 3, the storage capacitor 70 includes a relay layer 71 as a pixel potential side capacitor electrode connected to the high concentration drain region 1e of the TFT 30 and the pixel electrode 9a, and a capacitor line 300 as a fixed potential side capacitor electrode. A part thereof is formed so as to be opposed to each other through the dielectric film 75. According to the storage capacitor 70, it is possible to remarkably improve the potential holding characteristic in the pixel electrode 9a.

  The relay layer 71 is made of, for example, a conductive polysilicon film and functions as a pixel potential side capacitor electrode. However, the relay layer 71 may be composed of a single layer film or a multilayer film containing a metal or an alloy, similarly to the capacitor line 300 described later. The relay layer 71 has a function of relaying and connecting the pixel electrode 9a and the high-concentration drain region 1e of the TFT 30 via the contact holes 83 and 85, in addition to the function as a pixel potential side capacitor electrode.

  The capacitor line 300 is made of, for example, a conductive film containing a metal or an alloy and functions as a fixed potential side capacitor electrode. When viewed in a plan view, the capacitor line 300 is formed so as to overlap the region where the scanning line 3a is formed, as shown in FIG. More specifically, the capacitor line 300 includes a main line portion 300a extending along the scanning line 3a, and a protruding portion 300b protruding upward along the data line 6a from each portion intersecting the data line 6a in the drawing, A portion corresponding to the contact hole 85 is provided with a constricted portion 300c slightly constricted. Among these, the protrusion 300b contributes to an increase in the formation region of the storage capacitor 70 by using the region above the scanning line 3a and the region below the data line 6a (see FIG. 3). Such a capacitor line 300 is preferably made of a conductive light-shielding film containing a refractory metal. In addition to the function as a fixed-potential-side capacitor electrode of the storage capacitor 70, the light-shielding layer that shields the TFT 30 from incident light above the TFT 30. As a function. In addition, the capacitor line 300 preferably 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. As such a constant potential source, a constant potential source of a positive power source or a negative power source supplied to the data line driving circuit 101 or a constant potential supplied to the counter electrode 21 of the counter substrate 20 may be used.

  As shown in FIG. 3, the dielectric film 75 is, for example, a relatively thin HTO (High Temperature Oxide) film having a film thickness of about 5 to 200 nm, a silicon oxide film such as an LTO (Low Temperature Oxide) film, or a silicon nitride film. Consists of From the viewpoint of increasing the storage capacitor 70, the thinner the dielectric film 75 is, the better as long as the reliability of the film is sufficiently obtained.

  2 and 3, in addition to the above, a lower light-shielding film 11 a is provided below the TFT 30. The lower light-shielding film 11a is patterned in a lattice pattern, thereby defining an opening area of each pixel. The opening region is also defined by the data line 6a in FIG. 2 and the capacitor line 300 formed so as to intersect with the data line 6a. Similarly to the case of the capacitance line 300, the lower light-shielding film 11a is also extended from the image display area to the periphery thereof in order to prevent the potential fluctuation from adversely affecting the TFT 30. It may be connected to a potential source.

  A base insulating film 12 is provided under the TFT 30. In addition to the function of interlayer insulating the TFT 30 from the lower light-shielding film 11a, 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 the surface polishing or remains after cleaning. For example, the pixel switching TFT 30 has a function of preventing characteristic changes.

  In addition, a first interlayer insulating film 41 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 respectively formed on the scanning line 3a is formed.

  A relay layer 71 and a capacitor line 300 are formed on the first interlayer insulating film 41, and a contact hole 81 leading to the high-concentration source region 1d and a contact hole 85 leading to the relay layer 71 are opened on these, respectively. A holed second interlayer insulating film 42 is formed.

  In the first embodiment, the first interlayer insulating film 41 is fired at about 1000 ° C. to activate ions implanted into the polysilicon film constituting the semiconductor layer 1a and the scanning line 3a. You may plan. On the other hand, the stress generated in the vicinity of the interface of the capacitor line 300 may be reduced by not performing such firing on the second interlayer insulating film 42.

  A data line 6 a is formed on the second interlayer insulating film 42, and a third interlayer insulating film 43 in which a contact hole 85 leading to the relay layer 71 is formed is formed thereon.

  The surface of the third interlayer insulating film 43 is flattened by a CMP (Chemical Mechanical Polishing) process or the like, and reduces alignment defects of the liquid crystal layer 50 caused by steps due to various wirings and elements existing below the third interlayer insulating film 43. However, instead of or in addition to performing the planarization process on the third interlayer insulating film 43 in this way, the TFT array substrate 10, the base insulating film 12, the first interlayer insulating film 41, and the second interlayer insulating film 42 A flattening process may be performed by digging a groove in at least one of them and embedding a wiring such as the data line 6a or the TFT 30 or the like.

  In the electro-optical device according to the first embodiment having such a configuration, the following operational effects are achieved by the presence of the scanning line 3a including the narrow portion 3aa and the wide portion 3ab. Hereinafter, this effect will be described with reference to FIGS. 4 and 5. FIG. 4 shows the scanning line 3a including the narrow portion 3aa and the wide portion 3ab according to the first embodiment, the semiconductor layer 1a, the data line 6a, the capacitor line 300, the relay layer 71, and the contact hole 81 described above. And FIG. 5 is a perspective view of the same concept regarding a conventional electro-optical device that does not include such a scanning line 3a. 4 and 5 do not illustrate all the configurations shown in FIG. 2 and FIG. 3, but for example, some elements such as the dielectric film 75 constituting the storage capacitor 70 The illustration is appropriately omitted.

  First, looking at the conventional example of FIG. 5, since the scanning line 3a 'has a uniform width along the extending direction, for example, when oblique light L enters as shown in the figure. In addition, it can be seen that the light L reaches the channel region 1a ′ relatively easily. In this case, in the channel region 1a ′, a light leakage current is generated by excitation due to the entrance of the light L, and a constant current (light leakage current) flows even though the TFT 30 is off. Occurs. Accordingly, flicker or the like occurs on the image, and it is relatively difficult to display a high-quality image.

  However, according to the scanning line 3a according to the first embodiment, as shown in FIG. 4, even if the oblique light L similar to that in FIG. L does not reach the channel region 1a ′. Therefore, according to the first embodiment, it is possible to reduce the possibility of suffering the above-described disadvantage.

  In the first embodiment, as shown in FIGS. 2 and 4, since the wide portion 3ab and the data line 6a have regions overlapping each other with a width Wp, light enters the channel region 1a ′. Since the approach route to reach is more limited, the effects of suppressing the occurrence of light leakage current and displaying a high-quality image are more reliably achieved. Specifically, for example, in FIG. 4, a part of the light entering from the upper surface of the data line 6a is reflected or absorbed by the upper surface of the data line 6a, and the remaining part is the lower surface side of the data line 6a. Even if it reaches, it will be said that the progress is interrupted | blocked by the wide part 3ab.

  Furthermore, according to the first embodiment, in addition to the above, since the lower light shielding film 11a is provided, the light incident on the TFT 30 is shielded on both the upper side and the lower side, and a more reliable light shielding function is achieved. Demonstrate can be realized.

  In addition, in the said 1st Embodiment, although the narrow part 3aa and the wide part 3ab were made into the extended relationship, this invention is not limited to such a form. For example, after forming only the narrow portion 3ab as a conductive polysilicon film, the wide portion 3ab made of a light-shielding material is formed so as to be electrically connected to the polysilicon film, that is, The narrow portion 3aa and the wide portion 3ab may be electrically connected. In this case, since the narrow portion 3aa as the gate electrode can be formed with a material having good compatibility with the semiconductor layer 1a, it is possible to provide an electro-optical device with stable operation, and from the light shielding material. Since the wide portion 3ab is provided, an electro-optical device having a high light shielding function can be provided.

  In relation to this, in some cases, the scanning line 3a may have a two-layer structure in which the lower layer is made of a polysilicon film and the upper layer is made of a light shielding material. According to this, the portion which is required to function as a gate electrode and which faces the semiconductor layer 1a through the insulating film 2 is a polysilicon film having a good compatibility as described above, and therefore substantially the same function and effect as described above. Can be obtained.

  In the first embodiment, the wide portion 3ab is formed so as to extend in both directions in which the channel region 1a ′ extends when viewed from the edge of the narrow portion 3aa. The wide portion 3ab may be formed so as to extend from the edge to only one side.

(Second Embodiment)
Below, the 2nd Embodiment of this invention is described, referring FIG.6 and FIG.7. Here, FIGS. 6 and 7 are diagrams having the same concept as FIGS. 2 and 4, respectively, and are a plan view and a perspective view showing different scanning lines and the like. Note that the configuration of the electro-optical device according to the second embodiment is exactly the same as that of the above-described first embodiment unless otherwise specified in the following description, and therefore, the same reference numerals are shown in the drawings. The description of is omitted.

  In the second embodiment, unlike the first embodiment, which includes the scanning line 3a including the narrow portion 3aa and the wide portion 3ab, as shown in FIGS. 6 and 7, the narrow portion 301a and the wide portion are provided. An electrode part 301 including a part 301b is provided. As shown in FIG. 6, the electrode portion 301 is formed in an island shape on the TFT array substrate 10 in accordance with the formation region of the TFT 30, and each of the electrode portions 301 includes a narrow portion 301a facing the channel region 1a ′. And a wide portion 301b that does not face the channel region 1a ′. If attention is paid only to the narrow portion 301a and the wide portion 301b, it is understood that the general structure is substantially the same as that of the first embodiment. That is, the width of the narrow portion 301a is determined so as to match the channel length, and the wide portion 301b is projected from both edges of the narrow portion 301a (that is, in the + y direction in FIG. 6 and So as to protrude in any of the −y directions). On the other hand, the electrode portion 301 is electrically connected to the scanning line 3 formed under the TFT 30 with an interlayer insulating film interposed therebetween via a contact hole 88.

  Even in such a form, it is obvious that the light shielding effect by the wide portion 301b is achieved in substantially the same manner as the above-described wide portion 3ab.

  In addition, according to such a configuration, the degree of freedom of layout of the arrangement mode such as the TFT 30 closely related to the electrode portion 301 and the scanning line 3 is increased, and both are made of different materials, etc. It is also possible.

(Overall configuration of electro-optical device)
Hereinafter, the overall configuration of the electro-optical device according to the various embodiments configured as described above will be described with reference to FIGS. 8 and 9. 8 is a plan view of the TFT array substrate as viewed from the counter substrate 20 side together with the components formed thereon, and FIG. 9 is a cross-sectional view taken along line HH ′ of FIG.

  8 and 9, in the electro-optical device according to this embodiment, the TFT array substrate 10 and the 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 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, and is cured by ultraviolet rays, heating, or the like in order to bond the two substrates together. In addition, if the electro-optical device according to the present embodiment is applied to a liquid crystal device in which the liquid crystal device is small and performs enlarged display, such as a projector, the distance between the substrates (between the substrates) A glass fiber or a gap material (spacer) such as glass beads for setting the gap) to a predetermined value is dispersed. Alternatively, such a gap material may be included in the liquid crystal layer 50 if the electro-optical device is applied to a large-sized liquid crystal device such as a liquid crystal display or a liquid crystal television that performs the same size display.

  In a region outside the sealing material 52, a data line driving circuit 101 and an external circuit connection terminal 102 for driving the data line 6a by supplying an image signal to the data line 6a at a predetermined timing are provided on one side of the TFT array substrate 10. A scanning line driving circuit 104 for driving the scanning line 3a by supplying a scanning signal to the scanning line 3a at a predetermined timing is provided along two sides adjacent to the one side. Yes.

  Needless to say, if the delay of the scanning signal supplied to the scanning line 3a is not a problem, the scanning line driving circuit 104 may be provided on only one side. The data line driving circuit 101 may be arranged on both sides along the side of the image display area 10a.

  On the remaining side of the TFT array substrate 10, a plurality of wirings 105 are provided for connecting the scanning line driving circuits 104 provided on both sides of the image display region 10a. Further, at least one corner portion of the counter substrate 20 is provided with a conductive material 106 for electrical connection between the TFT array substrate 10 and the counter substrate 20.

  In FIG. 9, 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, in addition to the counter electrode 21, an alignment film is formed on the uppermost layer portion on the counter substrate 20. 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.

  On the TFT array substrate 10, in addition to the data line driving circuit 101, the scanning line driving circuit 104, etc., a sampling circuit for applying an image signal to the plurality of data lines 6a at a predetermined timing, and a plurality of data lines A precharge circuit for supplying a precharge signal of a predetermined voltage level in advance to the image signal to 6a, an inspection circuit for inspecting quality, defects, etc. of the electro-optical device during manufacture or at the time of shipment are formed. Also good.

  Further, instead of providing the data line driving circuit 101 and the scanning line driving circuit 104 on the TFT array substrate 10, for example, a driving LSI mounted on a TAB (Tape Automated Bonding) substrate is provided on the periphery of the TFT array substrate 10. You may make it connect electrically and mechanically through the provided anisotropic conductive film. Further, on the side on which the projection light of the counter substrate 20 enters and on the side on which the outgoing light of the TFT array substrate 10 exits, for example, a TN (Twisted Nematic) mode, a VA (Vertically Aligned) mode, a PDLC (Polymer Dispersed Liquid Crystal), respectively. ) A polarizing film, a retardation film, a polarizing plate, and the like are arranged in a predetermined direction according to the operation mode such as the mode and the normally white mode / normally black mode.

(Electronics)
Next, an overall configuration, particularly an optical configuration, of an embodiment of a projection color display device as an example of an electronic apparatus using the electro-optical device described in detail as a light valve will be described. FIG. 10 is a schematic cross-sectional view of the projection type color display device.

  In FIG. 10, a liquid crystal projector 1100 as an example of a projection type color display device according to the present embodiment prepares three liquid crystal modules including a liquid crystal device in which a drive circuit is mounted on a TFT array substrate, each of which is a light valve for RGB. It is configured as a projector used as 100R, 100G, and 100B. In the liquid crystal projector 1100, when projection light is emitted from a lamp unit 1102 of a white light source such as a metal halide lamp, light components R, G, and R corresponding to the three primary colors of RGB are obtained by three mirrors 1106 and two dichroic mirrors 1108. The light is divided into B and led to the light valves 100R, 100G and 100B corresponding to the respective colors. In particular, the B light is guided through a relay lens system 1121 including an incident lens 1122, a relay lens 1123, and an exit lens 1124 in order to prevent light loss due to a long optical path. The light components corresponding to the three primary colors modulated by the light valves 100R, 100G, and 100B are synthesized again by the dichroic prism 1112 and then projected as a color image on the screen 1120 via the projection lens 1114.

  The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit or idea of the invention that can be read from the claims and the entire specification, and an electro-optical device with such a change. In addition, electronic devices are also included in the technical scope of the present invention.

FIG. 3 is a circuit diagram illustrating an equivalent circuit of various elements, wirings, and the like provided in a plurality of matrix pixels that form an image display region in the electro-optical device according to the first embodiment of the present invention. 2 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 electro-optical device according to the first embodiment of the invention. FIG. It is AA 'sectional drawing of FIG. It is a perspective view which shows the three-dimensional arrangement | positioning aspect of the scanning line containing a narrow part and a wide part, a channel area | region, and the structure of the circumference | surroundings. It is a perspective view which shows the three-dimensional arrangement | positioning aspect with the scanning line in the conventional electro-optical apparatus, and its surrounding structure. FIG. 3 is a plan view showing the same concept as in FIG. 2 but showing an embodiment including an electrode portion including a narrow portion and a wide portion according to a second embodiment of the present invention. FIG. 5 is a plan view showing the same concept as in FIG. 4, but according to a second embodiment of the present invention, which includes an electrode part including a narrow part and a wide part. FIG. 5 is a plan view of the TFT array substrate in the electro-optical device according to the embodiment of the present invention, as viewed from the side of the counter substrate together with each component formed thereon. It is HH 'sectional drawing of FIG. 1 is a schematic cross-sectional view showing a color liquid crystal projector as an example of a projection type color display device which is an embodiment of an electronic apparatus of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a ... Semiconductor layer 1a '... Channel region 1b ... Low concentration source region 1c ... Low concentration drain region 1d ... High concentration source region 1e ... High concentration drain region 3a ... Scanning line 3aa ... Narrow part 3ab ... Wide part 6a ... Data line 9a ... Pixel electrode 10 ... TFT array substrate 11a ... Lower light shielding film 30 ... TFT
301 ... Electrode part 301a ... Narrow part 301b ... Wide part

Claims (12)

A pixel electrode on the substrate;
A pixel transistor for supplying an image signal to the pixel electrode by a switching operation;
A first wiring for supplying the image signal to the pixel transistor, a second wiring for supplying a scanning signal for controlling the switching operation to the pixel transistor, and the first wiring and the pixel transistor. A light shielding film disposed between and overlapping the pixel transistor;
A narrow portion serving as a gate electrode facing the channel region of the pixel transistor and a wide portion wider than the narrow portion and not facing the channel region, and formed in the wide portion region. And an electrode portion electrically connected to the second wiring by a contact hole.   2. The electro-optical device according to claim 1, wherein the electrode portion and the second wiring are electrically connected to each other through a contact hole at a position facing the channel region.   3. The electro-optical device according to claim 1, wherein at least a part of the wide portion includes a region overlapping the first wiring in a plan view.   4. The electro-optical device according to claim 1, wherein the wide portion includes a portion extending from the narrow portion. 5.   The electro-optical device according to claim 1, wherein the wide portion includes a portion connected from the narrow portion.   The electro-optical device according to claim 1, wherein the wide portion is made of a light shielding material.   The electro-optical device according to claim 1, wherein the second wiring or the electrode portion has a multilayer structure.   The wide portion extends in one or both of the extending directions of the channel region when viewed from the edge of the narrow portion. The electro-optical device described. The pixel electrodes are arranged in a matrix,
In the plan view, the channel region is sewn between pixel electrodes adjacent to each other across the first wiring and a long first gap extending between the pixel electrodes adjacent to each other with the second wiring interposed therebetween. 9. The electro-optical device according to claim 1, wherein the electro-optical device is formed in an intersection region where the extending second gap extends. The channel region, the source region and the drain region are formed to extend along the second gap;
The width of the narrow portion matches the length along the second gap of the channel region,
The electro-optical device according to claim 9, wherein the width of the wide portion has a value larger than the length.   The electro-optical device according to claim 1, further comprising a lower light-shielding film below the pixel transistor. An electronic apparatus comprising the electro-optical device according to claim 1.

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