JP4395807B2 - Electro-optical device substrate, electro-optical device, and electronic apparatus - Google Patents

Description

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

  A liquid crystal device which is an example of this type of electro-optical device is frequently used not only as a direct-view display but also as a light modulation means (light valve) of, for example, a projection display device. In particular, in the case of a projection display device, strong light from a light source is incident on a liquid crystal light valve, and this thin film transistor (TFT: Thin Film Transistor) in the liquid crystal light valve does not cause an increase in leakage current or malfunction. As described above, a light shielding film as a light shielding means for blocking incident light is built in the liquid crystal light valve. As for such a light shielding means or a light shielding film, for example, Patent Document 1 discloses a technique of shielding light by a scanning line functioning as a gate electrode in a channel region of a TFT. According to Patent Document 2, light reaching the channel region of the TFT is reduced by providing a plurality of light-shielding films formed on the channel region and a layer that absorbs internally reflected light. Patent Document 3 discloses a technique for reducing incident light incident on the channel region of the TFT as much as possible while ensuring a preferable operation of the TFT and narrowing the scanning line.

  On the other hand, in this type of electro-optical device, an image signal supplied to the pixel electrode is temporarily held in a region where a light shielding film is formed on the substrate, that is, a region where light is not transmitted on the substrate. Is provided with a storage capacitor for holding the potential of a predetermined period. Such a storage capacitor can also shield the TFT by using the electrode which is a component of the storage capacitor as a light shielding film.

JP 2004-4722 A Japanese Patent No. 3731447 JP 2003-262888 A

  However, for example, when light is applied to a junction region such as an LDD (Lightly Doped Drain) region formed between the channel region and the source / drain region, a light leakage current is generated in the junction region. There is a problem. For such problems, it is conceivable to provide a light shielding means on each junction region on both sides of the channel region. However, from the viewpoint of display performance, narrowing the aperture region through which light is substantially transmitted in the pixel. It is not preferable. On the other hand, when light is irradiated to the junction region formed between the source / drain region connected to the pixel electrode and the channel region, it is formed between the source / drain region connected to the data line and the channel region. The inventor of the present application has inferred that light leakage current in the TFT is likely to occur as compared with the case where light is irradiated to the bonded region.

  The present invention has been made in view of the above problems and the like. For example, the present invention is an electro-optical device such as a liquid crystal device driven by an active matrix method, and realizes a high aperture ratio while reducing a light leakage current in a TFT. It is an object to provide an electro-optical device substrate used in an electro-optical device that can effectively reduce generation, an electro-optical device including the electro-optical device substrate, and an electronic apparatus.

To solve the engaging Ru electrical device substrate is the object of the present invention, the substrate and, a plurality of data lines and a plurality of scanning lines which intersect each other on said substrate, said plurality of data lines and the plurality of A pixel electrode defined corresponding to the intersection of the scanning lines and formed in each of the plurality of pixels constituting the display region on the substrate; and (i) a non-opening that separates the opening regions of the plurality of pixels from each other. A channel region having a channel length along the first direction in a first region extending along the first direction in the display region of the opening region, and a data line side source / drain electrically connected to the data line A region, a pixel electrode side source / drain region electrically connected to the pixel electrode, a first junction region formed between the channel region and the data line side source / drain region, and the channel region And a semiconductor layer having a second junction region formed between the pixel electrode side source / drain regions, and (ii) a second region extending along a second direction intersecting the first direction among the non-opening regions. And a transistor having a gate electrode that overlaps the channel region in an intersecting region where the first region intersects each other, and is formed on an upper layer side than the semiconductor layer, and is formed in each of the first direction and the second direction. A first portion and a second portion extending along a light shielding portion having a crossing portion where the first portion and the second portion cross each other in the crossing region, and at least a part of the second bonding region , the Ri in the intersection region and Do heavy the intersection, wherein the gate electrode, and has a main portion in the second region extending along the second direction, contact the intersection region The main portion so that the main line portion does not overlap the second junction region Te has a recess made by cutting partially.

According to engagement Ru electrical-optical device substrate according to the present invention, for example, the image signal from the data line to the pixel electrode is controlled, it is possible to image display by a so-called active matrix method. The image signal is supplied from the data line to the pixel electrode through the transistor at a predetermined timing by turning on and off the transistor electrically connected between the data line and the pixel electrode. 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 has been.

The transistor includes a semiconductor layer including a channel region and a gate electrode overlapping with the channel region. The channel region has a channel length along the first direction in a first region extending along the first direction in the display region among the non-opening regions that separate the respective opening regions of the plurality of pixels. Here, the “opening region” according to the present invention is a region in a pixel through which light is substantially transmitted, for example, a region in which a pixel electrode is formed, and a liquid crystal or the like according to a change in transmittance. This is a region where the gradation of the emitted light that has passed through the electro-optical material can be changed. In other words, the “opening region” is a light shielding body such as a wiring, a light shielding film, and various elements in which the light condensed on the pixel does not transmit the light or the light transmittance is relatively smaller than that of the transparent electrode. It means the area that is not obstructed by. The “non-opening region” according to the present invention means a region where light contributing to display is not transmitted, for example, a region where a non-transparent wiring or electrode, or a light-shielding body such as various elements is arranged in a pixel. Means. The “first region” according to the present invention is a region that extends in the first direction of the display region among the non-open regions that extend in a lattice pattern in the display region so as to separate the adjacent open regions. More specifically, for example, the column direction of a plurality of pixels defined in a matrix on the substrate, that is, the arrangement direction in which a plurality of scanning lines are arranged. The data lines intersecting the plurality of scanning lines are formed in the first region, and the scanning lines are formed in the second region described later. The semiconductor layer has a first junction region formed between the channel region and the data line side source / drain region, and a second junction region formed between the channel region and the pixel electrode side source / drain region. That is, the semiconductor layer has a first junction region formed on the data line side source / drain region side and a second junction region formed on the pixel electrode side source / drain region side with respect to the channel region. .

  The gate electrode overlaps the channel region in a crossing region where the second region extending in the second direction intersecting the first direction and the first region intersect each other in the non-opening region. Here, the “second region” according to the present invention is, for example, a region where a scanning line intersecting with a data line is arranged in a non-opening region. The gate electrode may be a portion of the scan line that overlaps the channel region, or may be a conductive film provided separately from the scan line. Such a conductive film is electrically connected to the scanning line through connection means such as a contact hole. The “intersection area” according to the present invention is an area where the first area and the second area intersect, more specifically, located in the middle of each of the open areas of the four pixels adjacent to each other among the non-open areas. It is an area to do.

  The light shielding portion is formed on the upper layer side of the semiconductor layer in the stacked structure on the substrate, and the first portion and the second portion extending along each of the first direction and the second direction, and the first portion and The second part has an intersection formed by intersecting each other. The first portion may extend to one side along the first direction with respect to the intersecting region, or may extend toward both sides of the intersecting region along the first direction. The second portion extends from the intersecting region along the second direction. The second portion may extend on each side of the intersecting region along the second direction, or may extend on one side. In short, the light shielding portion only needs to have a portion extending in each of the first direction and the second direction intersecting each other with the intersection located in the intersection region as a reference. From the viewpoint of improving the light blocking property to block the light reaching the second junction region, it is preferable that the second portion extends to both sides of the intersecting region.

  Particularly in the present invention, at least a part of the second junction region overlaps the intersection in the intersection region. For example, the semiconductor layer may be arranged such that the second junction region overlaps the intersection in the intersection region and the first junction region does not overlap the intersection. As described above, the inventor of the present application speculates that a light leakage current is more likely to occur in the second junction region than in the first junction region during the operation of the transistor. The intersection portion and the second portion are irradiated to the second junction region as compared with the case where the second junction region does not overlap the intersection portion because at least a part of the second junction region overlaps the intersection portion. Light can be reduced. More specifically, in the first direction, incident light obliquely incident on the second bonding region at a large angle with respect to the normal direction of the surface along the surface of the first portion Since it extends along the first direction, it is shielded by the first portion. On the other hand, in the second direction, incident light that is obliquely incident on the second junction region at a large angle with respect to the normal direction of the surface along the surface of the second portion is along the intersection and the second direction. It is shielded by the second part that extends. Therefore, the light shielding property with respect to the second bonding region can be improved by overlapping the second bonding region at the intersection. Accordingly, it is not necessary to increase the width of the first portion or the second portion of the light shielding portion, for example, in order to improve the light shielding performance for the second junction region where the light leakage current is relatively likely to occur. In other words, according to the present invention, the aperture ratio is hardly decreased or not at all while improving the light shielding property for the second bonding region. Note that, from the viewpoint of improving the aperture ratio, it is desirable to narrow the widths of the first portion and the second portion of the light shielding portion. That is, it is desirable to make the intersection portion small. Compared with the second junction region, the first junction region where light leakage current is less likely to occur may not overlap the intersection.

As described above, according to the engagement Ru electrical-optical device substrate according to the present invention, without incurring unnecessary decrease in aperture ratio, can reduce display failure such as flicker caused by the occurrence of light leakage current An electro-optical device can be provided. Further, in the present invention, in particular, the gate electrode has a main line portion extending in the second direction in the second region, and the main line portion does not overlap the second junction region in the intersection region. The main line part has a recess partly cut away. Therefore, it is possible to overlap the second junction region closer to the center at the intersection, while preventing the gate electrode from overlapping the second junction region.

The engagement Ru electric optical apparatus for one embodiment of the substrate according to the present invention, the second junction region is an LDD region.

  According to this aspect, when the transistor is not operating, the off-current that flows in the data line side source / drain region and the pixel electrode side source / drain region can be reduced, and the decrease in the on-current that flows when the transistor is operating can be suppressed.

In another aspect of the engagement Ru electrical-optical device substrate according to the present invention, the gate electrode, prior Symbol first region, projecting on the side of the first junction region along the first direction from the main portion It has a convex part.

  In this aspect, since the channel length is set according to element characteristics required for the transistor, the size of the channel region or the semiconductor layer along the channel length so that the second junction region overlaps the intersection. Changing the length of the transistor changes the element characteristics of the original transistor. Therefore, even if the generation of the light leakage current is reduced, the device characteristics such as the switching characteristics required for the transistor are changed, and the advantage that the light leakage current can be reduced is obtained, but the original element characteristics are obtained. I can't do that. In particular, when the channel length is equal to or greater than the width of the main line portion of the gate electrode, the channel region protrudes from the main line portion along the first direction when at least a part of the second junction region overlaps the intersection.

  However, according to this aspect, since the gate electrode has the convex portion that protrudes from the main line portion along the first direction toward the first junction region, the gate electrode extends toward the first junction region along the first direction. Even when the channel region is provided so as to be shifted, the gate electrode can be placed over the channel region. Furthermore, since the convex portion overlaps the first portion extending along the first direction, the non-opening region is not increased. Therefore, the gate electrode can be overlaid on the channel region without reducing the aperture ratio.

The engagement Ru electric optical apparatus for another embodiment of the substrate according to the present invention, the light-shielding portion is disposed directly above the transistor.

  According to this aspect, it is possible to further reduce incident light that is obliquely incident on the semiconductor layer between the light shielding portion and the transistor.

The engagement Ru electric optical apparatus for another embodiment of the substrate according to the present invention, the light-shielding unit is a capacitive element having a clamping dielectric film between a pair of capacitor electrodes and the pair of capacitor electrodes, the capacitor element Holds the potential of the pixel electrode when an image signal is supplied to the pixel electrode via the data line.

  According to this aspect, by using the capacitive element also as the light shielding portion, it is possible to simplify the circuit configuration of the electro-optical device substrate and the layout of the wirings constituting the circuit as compared with the case where a separate light shielding film is provided.

  In the above-described aspect in which the light shielding portion is a capacitive element, each of the pair of capacitive electrodes may be formed of a metal film.

  According to this aspect, the capacitive element has a so-called MIM (Metal-Insulator-Metal) structure in which a metal film-dielectric film (insulating film) -metal film is laminated. According to such a capacitive element, power consumption consumed by the pair of capacitive electrodes can be reduced in accordance with various signals supplied to the pair of capacitive electrodes. In addition, since the conductivity is higher than that of the semiconductor layer, the potential corresponding to the image signal is immediately supplied to the pixel electrode in accordance with the supply of the image signal, so that the image quality can be improved.

  In the above-described aspect in which the light shielding portion is a capacitive element, one of the pair of capacitive electrodes may be formed of a semiconductor.

  According to this aspect, the capacitive element has a so-called MIS (Metal-Insulator-Semiconductor) structure in which a metal film-dielectric film (insulating film) -semiconductor film is laminated. According to such a capacitor element, for example, a semiconductor layer serving as one capacitor electrode can be electrically connected to the pixel electrode.

Electro-optical device according to the present invention is to solve the above problems, comprises an engagement Ru electrical-optical device substrate according to the present invention described above.

According to the electro-optical device according to the present invention includes the engagement Ru electrical-optical device substrate according to the present invention described above, it is possible to provide an electro-optical device having excellent display performance.

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

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

  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 an electro-optical device substrate, an electro-optical device, and an electronic apparatus according to the present invention will be described with reference to the drawings. In this embodiment, as an example of the electro-optical device, a TFT active matrix driving type liquid crystal device with a built-in driving circuit is taken as an example.
<First Embodiment>
First, the overall configuration of the liquid crystal device according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a plan view of the liquid crystal device as viewed from the counter substrate side together with the components formed on the TFT array substrate, and FIG. 2 is a cross-sectional view taken along the line H-H ′ in FIG. 1. is there.

  1 and 2, in the liquid crystal device according to the present embodiment, a TFT array substrate 10 and a counter substrate 20 are arranged to face each other. A liquid crystal layer 50 is sealed between the TFT array substrate 10 and the counter substrate 20. The TFT array substrate 10 and the counter substrate 20 are provided by a sealing material 52 provided in a seal region located around the image display region 10a as an example of the “display region” according to the present invention, in which a plurality of pixel portions are provided. They are glued together.

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

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

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

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

  The TFT array substrate 10 is a transparent substrate such as a quartz substrate, a glass substrate, or a silicon substrate. The counter substrate 20 is also a transparent substrate like the TFT array substrate 10.

  The TFT array substrate 10 is provided with a pixel electrode 9a, and an alignment film on which a predetermined alignment process such as a rubbing process has been performed is provided above the pixel electrode 9a. For example, the pixel electrode 9a is made of a transparent conductive film such as an ITO film, and the alignment film is made of an organic film such as a polyimide film.

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

  The counter substrate 20 may be provided with a lattice-shaped or striped light-shielding film. By adopting such a configuration, together with an upper light-shielding film provided as an upper capacitor electrode 300 to be described later, intrusion of incident light from the TFT array substrate 10 side into the channel region 1a ′ or its periphery is more reliably prevented. can do.

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

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

  Next, an electrical connection 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 forming the image display area of the liquid crystal device according to this embodiment.

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

  The scanning line 3a is electrically connected to the gate of the TFT 30, and the liquid crystal device 1 applies scanning signals G1, G2,..., Gm to the scanning line 3a in a pulse-sequential manner in this order at a predetermined timing. Is configured to do. The pixel electrode 9a is electrically connected to the drain of the TFT 30, and the image signal S1, S2,..., Sn supplied from the data line 6a is obtained by closing the TFT 30 as a switching element for a certain period. It is written at a predetermined timing. Image signals S 1, S 2,..., Sn written in a liquid crystal as an example of an electro-optical material via the pixel electrode 9 a are held for a certain period with the counter electrode formed on the counter substrate.

  The liquid crystal constituting the liquid crystal layer 50 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 70a, which is an example of the “light-shielding portion” according to the present invention, is provided in parallel with the liquid crystal capacitor formed between the pixel electrode 9a and the counter electrode. Electrically connected. The storage capacitor 70a 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 70a, the potential holding characteristic of the pixel electrode 9a is improved, and display characteristics such as contrast improvement and flicker reduction can be improved.

  Next, a specific configuration of the pixel portion that realizes the above-described operation will be described with reference to FIGS. FIG. 4 is a plan view of a plurality of adjacent pixel portions. 5 is a cross-sectional view taken along line AA ′ of FIG. 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. In FIG. 4 and FIG. 5, for convenience of explanation, illustration of a portion located above the pixel electrode 9a is omitted. In FIG. 5, the portion from the TFT array substrate 10 to the pixel electrode 9a constitutes an example of the “electro-optical device substrate” according to the present invention.

  In FIG. 4, the image display area 10a on the TFT array substrate 10 is composed of a plurality of pixels each provided with a pixel electrode 9a.

  A plurality of pixel electrodes 9 a are provided in a matrix on the TFT array substrate 10. Data lines 6a and scanning lines 3a are provided along the vertical and horizontal boundaries of the pixel electrode 9a. The scanning line 3a extends along the X direction, and the data line 6a extends along the Y direction so as to intersect the scanning line 3a. A pixel switching TFT 30 is provided at each of the locations where the scanning line 3a and the data line 6a intersect each other.

  The scanning line 3a, the data line 6a, the storage capacitor 70a, the lower light-shielding film 11a, the relay layer 93, and the TFT 30 are viewed on the TFT array substrate 10 in plan view, that is, an opening area of each pixel corresponding to the pixel electrode 9a (that is, In each pixel, the pixel is disposed in a non-opening region surrounding a region where light that actually contributes to display is transmitted or reflected. That is, the scanning lines 3a, the storage capacitors 70a, the data lines 6a, the lower light-shielding film 11a, and the TFTs 30 are arranged not in the opening area of each pixel but in the non-opening area so as not to disturb the display. Yes.

  4 and 5, the TFT 30 includes a semiconductor layer 1a and a part of the scanning line 3a serving as a gate electrode.

  The semiconductor layer 1a is made of, for example, polysilicon, and has a channel region 1a ′ having a channel length along the Y direction, 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. It consists of a line-side source / drain region 1e. That is, the TFT 30 has an LDD structure. The data line side LDD region 1b is an example of a first junction region according to the present invention, and the pixel electrode side LDD region 1c is an example of a second junction region according to the present invention.

  The data line side source / drain region 1d and the pixel electrode line side source / drain region 1e are formed substantially in mirror symmetry along the Y 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 line 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 line 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 line side source / drain region 1e, respectively. According to such an impurity region, when the TFT 30 is not operating, it is possible to reduce the off current flowing in the source region and the drain region, and to suppress the decrease in the on current flowing when the TFT 30 is operating. 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-aligned type in which the data line side source / drain region and the pixel electrode line side source / drain region are formed by implanting the concentration may be used.

  As shown in FIGS. 4 and 5, the gate electrode of the TFT 30 is formed as a part of the scanning line 3a, and is made of, for example, conductive polysilicon. The scanning line 3a has a main line portion extending along the X direction and a portion extending from the main line portion along the Y direction to both sides so as to overlap with a region where the main line portion of the channel region 1a ′ of the TFT 30 does not overlap. Have. A portion of the scanning line 3a that overlaps the channel region 1a ′ functions as a gate electrode. The gate electrode and the semiconductor layer 1a are insulated by a gate insulating film 2 (more specifically, two insulating films 2a and 2b).

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

  The base insulating film 12 is formed on the entire surface of the TFT array substrate 10 in addition to the function of interlayer insulating the TFT 30 from the lower light-shielding film 11a, and thus remains rough after polishing the surface of the TFT array substrate 10 and after cleaning. It has a function of preventing deterioration of the characteristics of the pixel switching TFT 30 due to dirt or the like.

  In FIG. 5, a storage capacitor 70 a is provided on the upper layer side of the TFT 30 on the TFT array substrate 10 via the interlayer insulating film 41. The storage capacitor 70a is formed by disposing the lower capacitor electrode 71m and the upper capacitor electrode 300 to face each other with the dielectric film 75a interposed therebetween.

  The upper capacitor electrode 300 is a pixel potential side capacitor electrode electrically connected to the pixel electrode line side source / drain region 1e of the TFT 30 and the pixel electrode 9a. More specifically, the upper capacitor electrode 300 is electrically connected to the relay layer 93 through the contact hole 84a, and together with the relay layer 93, the electrical connection between the pixel electrode line side source / drain region 1e and the pixel electrode 9a. A simple connection. In addition, the relay layer 93 is electrically connected to the pixel electrode 9a through a convex portion 93a that is a part of the relay layer 93 and a contact hole 85a that is electrically connected to the convex portion 93a. Therefore, the pixel electrode 9a and the upper capacitor electrode 300 are electrically connected.

  The upper capacitor electrode 300 is a non-transparent metal film that includes, for example, a metal or an alloy and is provided on the upper side of the TFT 30. The upper capacitor electrode 300 also functions as an upper light shielding film (or a built-in light shielding film) that shields the TFT 30. The upper capacitor electrode 300 is formed including a metal such as Al (aluminum) or Ag (silver).

  The upper capacitor electrode 300 is, for example, Ti (titanium), Cr (chromium), W (tungsten), Ta (tantalum), Mo (molybdenum), Pd (palladium) as the “conductive light shielding film” according to the present invention. ) Or the like, and may be composed of a single metal, an alloy, a metal silicide, a polysilicide, or a laminate of these. In this case, the function of the upper capacitor electrode 300 as the upper light shielding film can be further enhanced.

  The lower capacitor electrode 71m extends from the image display area 10a where the pixel electrode 9a is disposed to the periphery thereof. The lower capacitor electrode 71m is a fixed potential side capacitor electrode that is electrically connected to a constant potential source and maintained at a fixed potential.

  The lower capacitive electrode 71m is also a non-transparent metal film like the upper capacitive electrode 300. Therefore, the storage capacitor 70a has a so-called MIM structure having a three-layer structure of metal film-dielectric film (insulating film) -metal film. Here, the lower capacitor electrode 71m extends over a plurality of pixels and is shared by the plurality of pixels.

  Particularly in the present embodiment, since the lower capacitive electrode 71m is formed as a metal film, the consumption consumed by the entire liquid crystal device when the liquid crystal device is driven as compared with the case where the lower capacitive electrode 71m is configured using a semiconductor. Electric power can be reduced, and high-speed operation of elements in each pixel portion can be performed. Therefore, the liquid crystal device according to this embodiment can display a high-quality image.

  The dielectric film 75a has a single layer structure or a multilayer structure composed of a silicon oxide film such as an HTO (High Temperature Oxide) film, an LTO (Low Temperature Oxide) film, or a silicon nitride film.

  In FIG. 5, a data line 6a and a relay layer 93 are provided on the upper layer side of the storage capacitor 70a on the TFT array substrate 10 via the interlayer insulating film 42.

  The data line 6a is electrically connected to the data line side source / drain region 1d of the semiconductor layer 1a through a contact hole 81a penetrating the interlayer insulating films 41 and 42 and the gate insulating film 2. The data line 6a and the inside of the contact hole 81a are made of, for example, an Al (aluminum) -containing material such as Al—Si—Cu or Al—Cu, or a single Al layer, or a multilayer film including an Al layer and a TiN layer. The data line 6a also has a function of shielding the TFT 30 from light.

  The relay layer 93 is formed in the same layer as the data line 6 a on the interlayer insulating film 42. For the data line 6a and the relay layer 93, a thin film made of a conductive material such as a metal film is formed on the interlayer insulating film 42 using a thin film forming method, and the thin film is partially removed, that is, patterned. Thus, they are formed apart from each other. Therefore, since the data line 6a and the relay layer 93 can be formed in the same process, the manufacturing process of the device can be simplified.

  In FIG. 5, the pixel electrode 9a is formed on the upper layer side of the data line 6a via the interlayer insulating film 43. The pixel electrode 9a is electrically connected to the pixel electrode line side source / drain region 1e of the semiconductor layer 1a through the upper capacitor electrode 300, contact holes 83a, 84a and 85a, and the relay layer 93. The contact hole 85a is formed by depositing a conductive material constituting the pixel electrode 9a, such as ITO, on the inner wall of the hole formed in the interlayer insulating layer 43. An alignment film subjected to a predetermined alignment process such as a rubbing process is provided on the upper surface of the pixel electrode 9a.

  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). On the other hand, in the liquid crystal device according to the present embodiment, as described with reference to FIGS. 1 and 2, the scanning line driving circuit 104, the data line driving circuit 101, and the like are provided in the peripheral area located around the image display area 10a. The drive circuit is formed.

  Next, the planar shape of the pair of capacitor electrodes constituting the storage capacitor as the light shielding portion of the liquid crystal device according to the present embodiment will be described in detail with reference to FIG. FIG. 6 is a plan view showing a planar shape of a pair of capacitor electrodes constituting the storage capacitor of the liquid crystal device according to this embodiment. In FIG. 6, among the components constituting the pixel portion shown in FIG. 4, the TFT 30, the scanning line 3a, and the storage capacitor 70a are shown enlarged.

  As shown in FIG. 6, the upper capacitor electrode 300 constituting the storage capacitor 70a has a first portion 301 covering the data line side LDD region 1b and a second portion 302 covering the pixel electrode side LDD region 1c. Yes. Therefore, light incident on the data line side LDD region 1b and the pixel electrode side LDD region 1c from the upper layer side can be shielded by the first portion 301 and the second portion 302, respectively. Therefore, it is possible to reduce the occurrence of light leakage current in the data line side LDD region 1b and the pixel electrode side LDD region 1c.

  Particularly in the present embodiment, the second portion 302 of the upper capacitor electrode 300 is configured to have a width in the X direction wider than that of the first portion 301. That is, the width W2 of the second portion 302 in the X direction is wider than the width W1 of the first portion 301 in the X direction. Therefore, the light incident on the pixel electrode side LDD region 1c can be shielded more reliably than the light incident on the data line side LDD region 1b. That is, the light blocking property for blocking the light reaching the pixel electrode side LDD region 1c can be enhanced or enhanced than the light blocking property for blocking the light reaching the data line side LDD region 1b. Here, as will be described in detail later, the inventor of the present application speculates that, during the operation of the TFT 30, a light leakage current is more likely to occur in the pixel electrode side LDD region 1c than in the data line side LDD region 1b. ing. That is, it is presumed that when the pixel electrode side LDD region 1c is irradiated with light during the operation of the TFT 30, light leakage current in the TFT 30 is more likely to occur than when the data line side LDD region 1b is irradiated with light. is doing. Accordingly, by forming the second portion 302 so as to have a width W2 wider than the width W1 of the first portion 301, the light shielding property to the pixel electrode side LDD region 1c where the light leakage current is likely to occur is improved. And light leakage current flowing in the TFT 30 can be effectively reduced. In other words, the first portion 301 that covers the data line side LDD region 1b in which the light leakage current is relatively less likely to occur than the pixel electrode side LDD region 1c has a width W1 that is narrower than the second portion 302. By being formed in this manner, it is possible to prevent a wasteful decrease in the aperture ratio.

  That is, by forming the width W2 of the second portion 302 wider, the light shielding performance for the pixel electrode side LDD region 1c where light leakage current is relatively likely to occur is improved, and the width W1 of the first portion 301 is increased. By making it narrower, it is possible to prevent a wasteful decrease in the aperture ratio. In other words, only the light shielding property for the pixel electrode side LDD region 1c where the light leakage current is likely to occur is increased by so-called pinpoint, so that the light leakage current in the transistor is effectively reduced without causing a wasteful decrease in the aperture ratio. it can.

  Here, the reason why the light leakage current is more likely to occur in the pixel electrode side LDD region 1c than in the data line side LDD region 1b during the operation of the TFT 30 described above will be described with reference to FIGS. This will be described in detail.

  First, a measurement result obtained by measuring the magnitude of the drain current when the test TFT is irradiated with light will be described with reference to FIG. FIG. 7 is a graph showing the relationship between the light irradiation position and the drain current in the test TFT.

  In FIG. 7, data E1 scans a light spot (approximately 2.4 um visible light laser) sequentially from the drain region side to the source region side for a single TFT for test, ie, TEG (Test Element Group). The result of having measured the magnitude | size of the drain current at the time of irradiating is shown. TEG includes a channel region, a source region, and a drain region, a source side junction region formed at a junction between the channel region and the source region, and a drain side junction region formed at a junction between the channel region and the drain region. have.

  The horizontal axis in FIG. 7 indicates the light irradiation position where the light spot is irradiated. The boundary between the channel region and the drain side junction region, the boundary between the channel region and the source side junction region, and further the channel region is zero. It is said. The vertical axis in FIG. 7 indicates the magnitude of the drain current (however, the relative value normalized by a predetermined value). When the drain current flows from the drain region to the source region, the vertical axis is positive. When the drain current is flowing from the source region to the drain region, a negative value (that is, a negative value) is indicated.

  In FIG. 7, data E1 shows a positive value at any light irradiation position. That is, the drain current flows from the drain region toward the source region. Data E1 shows a larger value in the drain side junction region than in the source side junction region. That is, when the light spot is irradiated into the drain side junction region, the drain current becomes larger than when the light spot is irradiated into the source side junction region. That is, when the light spot is irradiated into the drain side junction region, the light leakage current becomes larger than when the light spot is irradiated into the source side junction region. Note that the drain current includes dark current (or subthreshold leakage, that is, leakage current that flows between the source region and the drain region even when light is not irradiated) and optical leakage current (or photoexcitation current, that is, Current generated by excitation of electrons due to light irradiation).

  Next, a mechanism in which the light leakage current is larger when the light spot is irradiated in the drain side junction region than in the case where the light spot is irradiated in the source side junction region will be described with reference to FIGS. Will be described with reference to FIG. FIG. 8 is a conceptual diagram showing the behavior of carriers when photoexcitation occurs in the drain side junction region. FIG. 9 is a conceptual diagram showing carrier behavior when photoexcitation occurs in the source-side junction region. In FIGS. 8 and 9, assuming the display of intermediate gradation in the pixel electrode 9a to which the above-described TFT 30 is electrically connected, the source potential (that is, the potential of the source region) is 4.5 V, and the gate potential. (That is, the potential of the channel region) is 0 V, and the drain potential (that is, the potential of the drain region) is 9.5 V. The horizontal axes in FIGS. 8 and 9 indicate each region in the semiconductor layer constituting the TEG. The vertical axes in FIGS. 8 and 9 indicate the potential of electrons (Fermi level). Since electrons have a negative charge, the higher the potential in each region, the smaller the potential of the electrons, and the lower the potential in each region, the greater the potential of the electrons.

  FIG. 8 shows the behavior of carriers when a light spot is irradiated to the drain side junction region formed between the channel region and the drain region, and photoexcitation occurs in the drain side junction region.

  In FIG. 8, it can be estimated that the light leakage current consists of two current components.

  That is, as the first current component, there is a current component due to movement of electrons generated by photoexcitation. More specifically, a current component (this current component) generated when electrons generated by photoexcitation in the drain side junction region (see “e” in the figure) move from the drain side junction region to the drain region having a lower potential. Is from the drain region to the source region).

  As the second current component, there is a current component due to movement of holes generated by photoexcitation (that is, holes, see “h” in the figure). More specifically, the bipolar effect generated by the movement of holes generated by photoexcitation in the drain side junction region from the drain side junction region to the channel region having a lower potential (that is, the electron potential is higher). This is the resulting current component. That is, the positive charge of the holes that have moved to the channel region reduces the potential of the channel region (that is, the so-called base potential) from the potential Lc1 to the potential Lc2, thereby increasing the number of electrons traveling from the source region to the drain region. (This current component flows from the drain region to the source region). Therefore, when photoexcitation occurs in the drain side junction region, the first and second current components are both in the direction of increasing the drain current (in other words, the collector current) (that is, the direction of flowing from the drain region to the source region). appear.

  FIG. 9 shows the behavior of carriers when a light spot is irradiated on the source side junction region formed between the channel region and the source region, and photoexcitation occurs in the source side junction region.

  In FIG. 9, the photoleakage current is different from the case where photoexcitation occurs in the drain side junction region described above with reference to FIG. 8, and the hole has a lower potential from the source side junction region (that is, the electron potential is more It can be assumed that the second current component due to the bipolar effect moving to the (high) channel region is dominant. That is, a first current component (this current component is expressed as a result of electrons generated by photoexcitation in the source side junction region (see “e” in the figure) moving from the source side junction region to the source region having a lower potential). , Which flows from the source region to the drain region) can be estimated to be less than the second current component caused by the bipolar effect (this current component flows from the drain region to the source region).

  In FIG. 9, since the base potential is pulled down from the potential Lc1 to the potential Lc3 by the second current component (that is, the positive charge of the holes moved to the channel region) due to the bipolar effect, the source region moves from the source region to the drain region. The current component due to the effect of increasing electrons flows from the drain region to the source region. On the other hand, the first current component described above flows from the source region to the drain region. That is, the first current component and the second current component flow in opposite directions. Here, in FIG. 7 again, when the light spot is irradiated to the source side junction region, the drain current (see data E1) shows a positive value. That is, in this case, the drain current flows from the drain region toward the source region. Therefore, it can be said that the first current component only suppresses the current component due to the bipolar effect, which is the dark current and the second current component, and is not large enough to direct the flow of the drain current from the source region to the drain region. .

  Further, since the potential difference between the channel region and the source region is smaller than the potential difference between the channel region and the drain region, the depletion region on the source region side (that is, the source side junction region) is depleted on the drain region side ( That is, it is narrower than the drain side junction region. For this reason, when the light spot is irradiated on the source-side junction region, the absolute amount of photoexcitation is smaller than when the light spot is irradiated on the drain-side junction region.

  As described above with reference to FIGS. 8 and 9, when photoexcitation occurs in the drain side junction region, both the first and second current components are generated in the direction of increasing the drain current. On the other hand, when photoexcitation occurs in the source side junction region, the first current component suppresses the second current component. Therefore, when the light spot is irradiated in the drain side junction region, the drain current becomes larger (that is, the light leakage current becomes larger) than when the light spot is irradiated in the source side junction region. .

  Next, when the pixel electrode side source / drain region is set to the drain potential and the light spot is irradiated into the pixel electrode side junction region, the data line side source / drain region is set to the drain potential and the data line side A mechanism in which the light leakage current becomes larger than that in the case where the light spot is irradiated in the junction region will be described with reference to FIGS. FIG. 10 is a conceptual diagram showing the behavior of carriers when photoexcitation occurs in the data line side junction region (in other words, the drain side junction region) when the data line side source / drain region is at the drain potential. is there. FIG. 11 is a conceptual diagram showing the behavior of carriers when photoexcitation occurs in the pixel electrode side junction region (in other words, the drain side junction region) when the pixel electrode side source / drain region is at the drain potential.

  In the following, a case where charge is held in a pixel portion including a pixel switching TFT and photoexcitation occurs will be considered. The difference from the case of assuming the TEG as described above is that the pixel electrode side of the pixel switching TFT can be in a floating state. A storage capacitor such as a storage capacitor 70a may be connected to the pixel electrode side of the pixel switching TFT. If the capacitance value is sufficiently large, the state is close to a fixed electrode as in the case of using the TEG described above. However, if the capacitance is not sufficiently large, it becomes a floating state or a state close to this. Here, it is assumed that the capacitance value is not sufficiently large.

  10 and 11, the liquid crystal device employs AC driving to prevent so-called burn-in. Here, it is assumed that halftone display is assumed, and the pixel electrode holds a negative field charge of 4.5 V and a positive field charge of 9.5 V alternately with 7 V as a reference potential. To do. For this reason, the source and drain of the pixel switching TFT are not fixed and change between the pixel electrode side source / drain region and the data line side source / drain region. That is, as shown in FIG. 10, when a negative field charge is held in the pixel electrode (that is, when the potential of the pixel electrode side source / drain region is lower than the potential of the data line side source / drain region), The pixel electrode side source / drain region is the source, whereas, as shown in FIG. 11, when the positive charge is held in the pixel electrode (that is, the potential of the pixel electrode side source / drain region is the data line side source). When it becomes higher than the potential of the drain region), the pixel electrode side source / drain region becomes the drain.

  In FIG. 10, when a negative field charge is held in the pixel electrode, the pixel electrode side source / drain region becomes the source (or emitter), and the data line side source / drain region becomes the drain (or collector). When photoexcitation occurs in the data line side junction region, which is the drain side junction region, as described above, the first current component due to the movement of electrons generated by photoexcitation and the second current component due to the bipolar effect are generated. . Here, when the second current component due to the bipolar effect occurs (that is, the base potential is pulled down from the potential Lc1 to the potential Lc2, and the source / drain region on the data line side that is the drain from the pixel electrode side source / drain region that is the source). When the electrons move to the region), the electrons are extracted from the pixel electrode side source / drain region in a floating state, and the potential of the pixel electrode side source / drain region as an emitter decreases from the potential Ls1 to the potential Ls2 ( The potential rises). That is, when photoexcitation occurs in the data line side junction region which is the drain side junction region, the base potential is lowered and the potential of the pixel electrode side source / drain region as the emitter is also lowered. In other words, when photoexcitation occurs in the data line side junction region, which is the drain side junction region, the emitter potential also increases as the base potential increases. For this reason, the drain current (that is, the emitter current and the collector current) is suppressed.

  On the other hand, in FIG. 11, when a positive field charge is held in the pixel electrode, the data electrode side source / drain region becomes the source (or emitter), and the pixel electrode side source / drain region becomes the drain (or collector). Become. When photoexcitation occurs in the pixel electrode side junction region which is the drain side junction region, as described above, the first current component due to the movement of electrons generated by photoexcitation and the second current component due to the bipolar effect are generated. . Here, since the source / drain region on the data line side serving as the source is connected to the data line, unlike the pixel electrode, it is not in a floating state and the potential does not change. When the second current component due to the bipolar effect is generated (that is, the base potential is lowered from the potential Lc1 to the potential Lc2, and electrons are transferred from the source / drain region on the data line side as the source to the pixel electrode source / drain region as the drain. When the electrons move, electrons flow into the pixel electrode side source / drain region in a floating state, and the potential of the pixel electrode side source / drain region as a collector increases from the potential Ld1 to the potential Ld2 (the potential decreases). ). However, unlike the above-described decrease in the potential of the pixel electrode side source / drain region as the source, the increase in the potential of the pixel electrode side source / drain region as the collector has little function of suppressing the drain current. Since the drain current (ie, collector current) is almost determined by the magnitude of the base potential with respect to the emitter potential, the drain current is hardly suppressed even if the collector potential is lowered. In other words, in the saturation region of the bipolar transistor. It is in the state.

  As described above with reference to FIGS. 10 and 11, when a positive field charge is held in the pixel electrode (that is, when the pixel electrode side source / drain region serves as a drain), the bipolar effect is reduced. The resulting second current component is hardly suppressed, whereas when the negative electrode charge is held in the pixel electrode (that is, when the data-side source / drain region becomes the drain), it is caused by the bipolar effect. The second current component is suppressed due to an increase in potential of the pixel electrode side source / drain region which is in a floating state. That is, when the pixel electrode side source / drain region becomes the drain, the drain current increases due to the light leakage current, compared to when the data side source / drain region becomes the drain.

  Here, FIG. 12 shows the waveform of the pixel electrode potential when relatively strong light is irradiated to the entire pixel switching TFT.

  In FIG. 12, data E2 indicates that the variation Δ1 in the pixel electrode potential when the positive charge is held in the pixel electrode (when the pixel electrode potential is the potential V1) is the negative field charge held in the pixel electrode. This indicates that it is larger than the fluctuation Δ2 of the pixel electrode potential when the pixel electrode potential is set to the potential V2. That is, it is indicated that the positive field charge is less likely to be held than the negative field charge in the pixel electrode (that is, light leakage is likely to occur). This is because when the pixel electrode holds a positive field charge (that is, when the pixel electrode side source / drain region becomes the drain), the pixel electrode holds a negative field charge (that is, This is consistent with the mechanism described above in which light leakage current is more likely to occur than when the data line side source / drain region becomes the drain.

  As described above in detail with reference to FIGS. 7 to 12, the drain current tends to increase when photoexcitation occurs in the drain side junction region in the pixel switching TFT. Further, when the pixel electrode side source / drain region becomes the drain, the drain current tends to increase (in other words, when the data line side source / drain region becomes the drain, the current component due to the bipolar effect is suppressed. ing). Therefore, as in the liquid crystal device according to the present embodiment, the light shielding property for the pixel electrode side LDD region that is the pixel electrode side junction region is higher than the light shielding property for the data line side LDD region that is the data line side junction region. Thus, it is possible to effectively obtain a high light shielding property while maintaining a high aperture ratio.

As described above, according to the liquid crystal device including the substrate for the electro-optical device according to the present embodiment, display of flicker or the like caused by the occurrence of the light leakage current without causing a wasteful decrease in the aperture ratio. Defects can be reduced.
<Second Embodiment>
Next, a liquid crystal device according to a second embodiment will be described with reference to FIG. FIG. 13 is a plan view having the same concept as in FIG. 6 in the second embodiment. In FIG. 13, the same components as those in the first embodiment shown in FIG. 6 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  In FIG. 13, the liquid crystal device according to the second embodiment includes a TFT 30, a scanning line 3a, and a storage capacitor 70b.

  The TFT 30 includes a semiconductor layer 1a including a channel region 1a ′ and a gate electrode 3b formed of a portion of the scanning line 3a that overlaps the channel region 1a ′. The channel region 1a ′ has a channel length L1 along the Y direction in the first region D1 extending along the Y direction in the display region among the non-opening regions that separate the respective opening regions of the plurality of pixels. . The semiconductor layer 1a includes a data line side LDD region 1b formed between the channel region 1a 'and the data line side source / drain region 1d, and a pixel electrode side formed between the channel region 1a' and the pixel electrode side source / drain region 1c. LDD region 1c. In other words, the semiconductor layer 1a has a pixel electrode formed on the data line side LDD region 1b formed on the data line side source / drain region 1d side and the pixel electrode side source / drain region 1e side on the basis of the channel region 1a ′. Side LDD region 1c.

  The scanning line 3a is formed along the X direction in the second region D2 extending in the X direction in the non-opening region. A part of the scanning line 3a is formed as a gate electrode 3b. The gate electrode 3b overlaps the channel region 1a ′ in the intersecting region where the first region D1 and the second region D2 intersect each other.

  The storage capacitor 70b includes an upper capacitor electrode 300b, a lower capacitor electrode 71n, and a dielectric film sandwiched between these capacitor electrodes. In the storage capacitor 70b, the planar shapes of the upper capacitor electrode 300b and the lower capacitor electrode 71n are different from the planar shapes of the upper capacitor electrode 300 and the lower capacitor electrode 71m of the storage capacitor 70a in the first embodiment described above. In other respects, the storage capacitor 70b is configured in substantially the same manner as the storage capacitor 70a.

  The storage capacitor 70b includes a first portion Py extending along the Y direction from an intersecting region where the first region D1 and the second region D2 intersect each other, and a second portion Px extending along the X direction from the intersecting region. The first portion Py and the second portion Px have an intersection Cd where they intersect each other in the intersection region.

  The first portion Py includes a lower capacitance electrode Y-side extension portion 71ny extending along the Y direction in the lower capacitance electrode 71n, and an upper capacitance electrode Y-side extension portion 300by extending along the Y direction in the upper capacitance electrode 300b. And a portion of the dielectric film extending between the lower capacitive electrode Y side extending portion 71my and the upper capacitive electrode Y side extending portion 300by. The second portion Px includes a lower capacitance electrode X side extending portion 71nx extending along the X direction in the lower capacitance electrode 71n, and an upper capacitance electrode X side extending portion 300bx extending along the X direction in the upper capacitance electrode 300b. And a portion of the dielectric film extending between the lower capacitive electrode X side extending portion 71nx and the upper capacitive electrode X side extending portion 300bx.

  In the present embodiment, in particular, at least a part of the pixel electrode side LDD region 1c overlaps the intersection Cd and the TFT array substrate 10 in plan view on the intersection region. The data line side LDD region 1b does not overlap the intersection Cd. As described in detail with reference to FIGS. 7 to 12, the inventor of the present application has a relatively higher light leakage current in the pixel electrode side LDD region 1 c than in the data line side LDD region 1 b during the operation of the TFT 30. I guess it is likely to occur. The intersection portion Cd and the second portion Px have the pixel electrode side LDD compared to the case where the pixel electrode side LDD region 1c does not overlap the intersection portion Cd because at least a part of the pixel electrode side LDD region 1c overlaps the intersection portion Cd. The light irradiated to the area | region 1c can be reduced. More specifically, in the Y direction, incident light obliquely incident on the pixel electrode side LDD region 1c at a large angle with respect to the normal direction of the surface along the surface of the first portion Py is the first portion. Since Py extends along the Y direction, it is shielded from light by the first portion Py. On the other hand, in the X direction, incident light obliquely incident on the pixel electrode side LDD region 1c at a large angle with respect to the normal direction of the surface along the surface of the second portion Px is incident on the intersection Cd and the X direction. The light is shielded by the second portion Px extending along. Therefore, the light shielding property with respect to the pixel electrode side LDD region 1c can be enhanced by overlapping the pixel electrode side LDD region 1c on the intersection Cd. Therefore, it is not necessary to increase the width of the first portion Py or the second portion Px of the storage capacitor 70b in order to improve the light shielding property with respect to the pixel electrode side LDD region 1c where light leakage current is relatively likely to occur. That is, according to the liquid crystal device according to the present embodiment, the aperture ratio is hardly lowered or not lowered while improving the light shielding property with respect to the pixel electrode side LDD region 1c. From the viewpoint of improving the aperture ratio, it is desirable to narrow the widths of the first portion Py and the second portion Px of the storage capacitor 70b. That is, it is desirable to make the intersection Cd small.

  It should be noted that the data line side LDD region 1b in which light leakage current is less likely to occur than the pixel electrode side LDD region 1c may not overlap the intersection Cd. Even in this case, the data line side LDD region 1b is shielded from light by overlapping with the first portion Py of the storage capacitor 70b, and little or no light leakage current is generated in practice.

  Further, in this embodiment, in particular, the gate electrode 3b includes the main line portion 3bx extending along the X direction in the second region D2, and the data line side LDD region 1b along the Y direction from the main line portion 3bx in the first region D1. And a convex portion 3by protruding to the side. Since the channel length L1 of the channel region 1a ′ is set according to the element characteristics required for the TFT 30, the size of the channel region 1a ′ or the channel length so that the pixel electrode side LDD region 1c overlaps the intersection Cd. Changing the length of the semiconductor layer 1a along L1 changes the original element characteristics of the TFT 30. Therefore, even if the pixel electrode side LDD region 1c overlaps the intersecting portion Cd, even if the generation of the light leakage current is reduced, the device characteristics itself such as the switching characteristics required for the TFT 30 are changed. However, the original device characteristics cannot be obtained. In particular, as in the present embodiment, when the channel length L1 is equal to or greater than the width W1 of the main line portion 3bx of the gate electrode 3b, at least a part of the pixel electrode side LDD region 1c intersects if no measures are taken. By overlapping with the portion Cd, the channel region 1a ′ protrudes from the main line portion 3bx along the Y direction.

However, in the present embodiment, in particular, as described above, the gate electrode 3b has the protruding portion 3by protruding from the main line portion 3bx to the data line side LDD region 1b side along the Y direction. Therefore, even if the channel region 1a ′ is provided so as to be shifted to the data line side LDD region 1b along the Y direction, the gate electrode 3b can be disposed over the channel region 1a ′. Furthermore, since the convex portion 3by overlaps the first portion Py extending along the Y direction, the non-opening region is not increased. Therefore, the gate electrode 3b can be placed over the channel region 1a ′ without reducing the aperture ratio.
<Third Embodiment>
A liquid crystal device according to a third embodiment will be described with reference to FIGS. FIG. 14 is a plan view having the same concept as FIG. 4 in the third embodiment. 15 is a cross-sectional view taken along the line BB ′ of FIG. FIG. 16 is a plan view having the same concept as in FIG. 6 in the third embodiment. 14 to 16, the same reference numerals are given to the same components as the components according to the first embodiment shown in FIGS. 1 to 6, and the description thereof will be omitted as appropriate.

  As shown in FIGS. 14 and 15, the liquid crystal device according to the third embodiment includes a TFT 30c instead of the TFT 30 in the first embodiment described above with reference to FIGS. 4 and 15, and a storage capacitor 70a. Unlike the liquid crystal device according to the first embodiment described above, the storage capacitor 70c is provided instead of the storage capacitor 70c, and the scanning line 3c is provided instead of the scanning line 3a. The configuration is substantially the same as that of the liquid crystal device according to the embodiment.

  As shown in FIGS. 14 and 15, the TFT 30c includes a semiconductor layer 1a and a part of the scanning line 3c serving as a gate electrode. The semiconductor layer 1a includes a channel region 1a ′ having a channel length along the Y direction, a data line side LDD region 1b and a pixel electrode side LDD region 1c, and a data line side source / drain region 1d and a pixel electrode line side source / drain region 1e. Consists of. The data line side source / drain region 1d has a contact hole 81b opened through the interlayer insulating film 42, the insulating film 61, the interlayer insulating film 41, and the gate insulating film 2 (specifically, the insulating films 2a and 2b). And the data line 6a are electrically connected to each other. The pixel electrode side source / drain region 1e is electrically connected to a lower capacitor electrode 71s, which will be described later, through a contact hole 83b opened through the interlayer insulating film 41 and the gate insulating film 2.

  As shown in FIG. 14, in this embodiment, each of the plurality of TFTs 30c includes a data line side source / drain region 1d and a pixel in a pair of TFTs 30c arranged adjacent to each other in the Y direction (that is, the column direction). The electrode-side source / drain regions 1e are disposed so that the directions thereof are opposite to each other, and the contact holes 81b for electrically connecting the data-line-side source / drain regions 1d of the pair of TFTs 30c to the data lines 6a are common. It has become.

  That is, in FIG. 14, if the vertical direction is the Y direction, the pair of TFTs 30c are TFTs that are vertically inverted or mirrored vertically. The plurality of TFTs 30c arranged in mirror symmetry in this way are the data line side source / drain regions 1d of the i-th TFT 30c (i) in the Y direction (where i is an even or odd number). The contact hole 81b that connects the data line 6a and the contact hole 81b that connects the data line side source / drain region 1d of the (i + 1) th TFT 30c (i + 1) and the data line 6a in the Y direction are common. Therefore, the data line side source / drain region 1d of both the pair of TFTs 30c (that is, the TFT 30c (i) and the TFT 30c (i + 1)) is electrically connected to the data line 6a only by one contact hole 81b. That is, the number of contact holes is dramatically increased as compared with the case where TFTs 30c are provided separately for each pixel as usual and the electrical connection from the data line side source / drain region 1d to the data line 6a is made separately for each TFT 30c. Can be reduced. As a result, the pitch can be narrowed, and the liquid crystal device can be reduced in size and definition.

  In FIG. 15, a storage capacitor 70 c is provided on the upper layer side through the interlayer insulating film 41 than the TFT 30 c on the TFT array substrate 10. The storage capacitor 70c is formed by disposing the lower capacitor electrode 71s and the upper capacitor electrode 300c so as to face each other through the dielectric film 75a.

  The upper capacitor electrode 300c is a fixed potential side capacitor electrode, and the lower capacitor electrode 71s is a pixel potential side capacitor electrode electrically connected to the pixel electrode side source / drain region 1e of the TFT 30c via the contact hole 83b. The lower capacitor electrode 71s is formed of a semiconductor such as polysilicon. Accordingly, the storage capacitor 70c has a so-called MIS structure. The lower capacitor electrode 71 s is electrically connected to the relay layer 93 through a contact hole 84 b opened through the interlayer insulating film 42 and the insulating film 61. The lower capacitance electrode 71s has a function as a light absorption layer or a light shielding film disposed between the upper capacitance electrode 300 as an upper light shielding film and the TFT 30c, in addition to the function as a pixel potential side capacitance electrode. The data line 6a is electrically connected to the high concentration source region 1d through a contact hole 81b that penetrates the interlayer insulating film 41, the insulating film 61, and the second interlayer insulating film. An insulating film 61 is partially interposed between the interlayer insulating films 41 and 42.

  In FIG. 14, the lower capacitor electrodes 71s are separated from each other for each pixel. Therefore, the image signal supplied via the data line 6a is supplied for each pixel in accordance with the switching operation of the TFT 30c. Since the upper capacitor electrode 300c extends across a plurality of pixels along the X direction, the electrode area is larger than that of the lower capacitor electrode 71s by being shared by the plurality of pixels. However, since the upper capacitor electrode 300c is made of a metal film such as Al, an increase in electrical resistance due to an increase in electrode area can be suppressed as compared with the case where the upper capacitor electrode 300c is formed of a semiconductor. Therefore, power consumption during operation of the liquid crystal device can be reduced, and various elements in each pixel can be driven at high speed, and there is an advantage that deterioration in responsiveness when an image is displayed by the liquid crystal device can be suppressed. Such an advantage is not limited to the case where the upper capacitor electrode 300c is formed so as to extend over pixels adjacent to each other along the X direction as in the present embodiment. Appears more prominently when it is formed over a plurality of pixels so as to occupy a larger area in the image display region 10a.

  14 and 16, the storage capacitor 70c includes a first portion Py extending along the Y direction from an intersection region where the first region D1 and the second region D2 intersect each other, and an X direction from the intersection region. The extending second portion Px and the intersecting portion Cd where the first portion Py and the second portion Px intersect each other in the intersecting region.

  The first portion Py includes a lower capacitance electrode Y-side extension portion 71sy extending along the Y direction in the lower capacitance electrode 71s and an upper capacitance electrode Y-side extension portion 300cy extending along the Y direction in the upper capacitance electrode 300c. And a portion of the dielectric film extending between the lower capacitor electrode Y side extending portion 71sy and the upper capacitor electrode Y side extending portion 300cy. The second portion Px includes a lower capacitor electrode X side extending portion 71sx extending along the X direction in the lower capacitor electrode 71s, and an upper capacitor electrode X side extending portion 300cx extending along the X direction in the upper capacitor electrode 300c. And a portion of the dielectric film extending between the lower capacitive electrode X side extending portion 71sx and the upper capacitive electrode X side extending portion 300cx.

  In the present embodiment, as in the liquid crystal device according to the second embodiment described above, at least a part of the pixel electrode side LDD region 1c is viewed in plan on the intersection Cd and the TFT array substrate 10 in the intersection region. , Overlap each other. The data line side LDD region 1b does not overlap the intersection Cd. Therefore, the intersection portion Cd and the second portion Px have pixel electrodes compared to the case where the pixel electrode side LDD region 1c does not overlap the intersection portion Cd because at least a part of the pixel electrode side LDD region 1c overlaps the intersection portion Cd. The light irradiated to the side LDD region 1c can be reduced.

  As shown in FIGS. 14 and 16, in the present embodiment, in particular, the scanning line 3c shared as the gate electrode of the TFT 30 includes a main line portion 3c1 extending in the X direction in the second region D2, and the first region D1 and In the intersecting region where the second regions D2 intersect each other, the main line portion 3c1 is partially cut away so that the main line portion 3c1 does not overlap the pixel electrode side source / drain region 1c, and the main line portion 3c1 extends in the Y direction. Along the data line side source / drain region 1d. Therefore, a part of the scanning line 3c can be provided as a gate electrode so as not to overlap the pixel electrode side source / drain region 1c but to overlap the channel region 1a.

  That is, since the scanning line 3c has the recess 150, even when the scanning line 3c extends along the X direction, the scanning line 3c is shared by a plurality of pixels arranged along the X direction. However, a part of the scanning line 3c can be provided as a gate electrode so as not to overlap the pixel electrode side source / drain region 1c but to overlap the channel region 1a ′ in each pixel. Further, even if the channel region 1a ′ is shifted to the data line side source / drain region 1d along the Y direction by the projection 160, the scanning line 3c is partially overlapped with the channel region 1a ′. Can be arranged as a gate electrode. The gate electrode may be shared with a part of the scanning line 3c, or may be provided separately from the scanning line 3c and electrically connected to the scanning line 3c by connection means such as a contact hole. Good.

In FIG. 14, as described above, the pair of TFTs 30c have a common contact hole 81b, which is a TFT whose mirror is inverted, so that the pair of scanning lines 3c corresponding to the pair of TFTs 30c is also an upper and lower mirror. The scan line is inverted. That is, a pair of TFTs 30c arranged adjacent to each other in the Y direction corresponds to the pair of TFTs 30c according to the arrangement of the data line side LDD region 1b and the pixel electrode side LDD region 1c being reversed. The scanning lines 3c are arranged so that the directions of the concave portions 150 and the convex portions 160 are opposite to each other. With this configuration, the liquid crystal device can be reduced in size and definition, and display defects such as flicker caused by the occurrence of light leakage current can be reduced.
<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. 17 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. 17, 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. 17, a mobile personal computer, a mobile phone, a liquid crystal television, a viewfinder type, a monitor direct view type video tape recorder, a car navigation device, a pager, and an electronic notebook , Calculators, word processors, workstations, videophones, POS terminals, devices with touch panels, and the like. Needless to say, the present invention can be applied to these various electronic devices.

  In addition to the liquid crystal device described in the above embodiment, the present invention also includes a reflective liquid crystal device (LCOS) in which elements are formed on a silicon substrate, a plasma display (PDP), a field emission display (FED, SED), The present invention can also be applied to an organic EL display, a digital micromirror device (DMD), an electrophoresis apparatus, and the like.

  The present invention is not limited to the above-described embodiments, 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. For electro-optical devices with such changes A substrate, an electro-optical device including the substrate for the electro-optical device, and an electronic apparatus including the electro-optical device are 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 the HH 'sectional view taken on the line 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. 2 is a plan view of a plurality of pixel units of the liquid crystal device according to the first embodiment. FIG. FIG. 5 is a cross-sectional view taken along line AA ′ in FIG. 4. It is a top view which shows the planar shape of the storage capacity of the liquid crystal device which concerns on 1st Embodiment. It is a graph which shows the relationship between the light irradiation position in TEG, and drain current. It is a conceptual diagram which shows the behavior of a carrier when photoexcitation generate | occur | produces in the drain side junction area | region. It is a conceptual diagram which shows the behavior of the carrier when optical excitation generate | occur | produces in the source side junction area | region. It is a conceptual diagram which shows the behavior of a carrier when photoexcitation generate | occur | produces in the data line side junction area | region when a data line side source drain region is made into drain electric potential. It is a conceptual diagram which shows the behavior of a carrier when photoexcitation generate | occur | produces in the pixel electrode side junction area | region when the pixel electrode side source drain region is made into drain potential. It is a wave form diagram which shows the waveform of the pixel electrode potential at the time of irradiating light to the whole TFT for pixel switching. It is a top view of the same meaning as FIG. 6 in 2nd Embodiment. It is a top view of the same meaning as FIG. 4 in 3rd Embodiment. It is the BB 'sectional view taken on the line of FIG. It is a top view of the same meaning as FIG. 6 in 3rd Embodiment. 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, 7 ... Sampling circuit, 3a, 3c ... scanning line, 3b ... gate electrode, 6a ... data line, 9a ... pixel electrode, 10 ... TFT array substrate, 10a ... image display area, 20 ... counter substrate, 21 ... counter electrode, 23 ... light shielding film, 30 ... TFT, 50 ... Liquid crystal layer, 70a, 70b, 70c ... Storage capacitor, 71m, 71n, 71s ... Lower capacitor electrode, 81a, 83a ... Contact hole, 101 ... Data line drive circuit, 102 ... External circuit connection terminal, 104 ... Scanning line drive circuit 106... Vertical conduction terminal 150 .. recessed portion 160 .. recessed portion 300 300 b 300 c upper capacitor electrode 301 first portion , 302 ... second portion, intersection ... Cd, D1 ... first region, D2 ... second region, Px ... first portion, Py ... second portion

Claims (8)

A substrate,
A plurality of data lines and a plurality of scanning lines intersecting each other on the substrate;
A pixel electrode provided corresponding to an intersection of the plurality of data lines and the plurality of scanning lines and formed on each of a plurality of pixels constituting a display region on the substrate;
(I) a channel region having a channel length along the first direction in a first region extending along the first direction in the display region among the non-opening regions separating the opening regions of the plurality of pixels from each other; A data line side source / drain region electrically connected to the data line; a pixel electrode side source / drain region electrically connected to the pixel electrode; and the channel region and the data line side source / drain region. A semiconductor layer having a formed first junction region and a second junction region formed between the channel region and the pixel electrode side source / drain region; and (ii) the first of the non-opening regions. A second region extending along a second direction intersecting the direction and a transistor having a gate electrode overlapping the channel region in a crossing region where the first region intersects each other And Star,
A first portion and a second portion that are formed on the upper layer side of the semiconductor layer and extend along each of the first direction and the second direction, and the first portion and the second portion in the intersection region Including a light shielding portion having crossing portions that cross each other,
At least a portion of the second junction region overlaps the intersection in the intersection region;
The gate electrode includes a main line portion extending along the second direction in the second region, and a main line portion partially cut away so that the main line portion does not overlap the second junction region in the intersection region. A substrate for an electro-optical device, comprising: a concave portion that is formed, and a convex portion that protrudes from the main line portion along the first direction toward the first bonding region in the first region.   The electro-optical device substrate according to claim 1, wherein the second bonding region is an LDD region.   The electro-optical device substrate according to claim 1, wherein the light-shielding portion is disposed immediately above the transistor. The light shielding portion is a capacitive element having a pair of capacitive electrodes and a dielectric film sandwiched between the pair of capacitive electrodes,
The said capacitive element hold | maintains the electric potential of the said pixel electrode, when an image signal is supplied to the said pixel electrode via the said data line. Electro-optic device substrate.   The electro-optical device substrate according to claim 4, wherein each of the pair of capacitive electrodes is formed of a metal film.   The electro-optical device substrate according to claim 4, wherein one of the pair of capacitive electrodes is formed of a semiconductor.   An electro-optical device comprising the electro-optical device substrate according to claim 1.   An electronic apparatus comprising the electro-optical device according to claim 7.

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