Electro-optical device and electronic apparatus Number:7,161,193 from the United States Patent and Trademark Office (PTO) owispatent There is provided an electro-optical device including, above a substrate, data lines extending in a first direction, scanning lines extending in a second direction and intersecting the data lines, pixel electrodes and thin film transistors disposed so as to correspond to intersection regions of the data lines and the scanning lines; and storage capacitors electrically connected to the thin film transistors and the pixel electrodes, the thin film transistors including semiconductor layers having channel regions which extend in a longitudinal direction and channel adjacent regions which extend further from the channel regions in the longitudinal direction, and the scanning lines including light-shielding parts disposed at sides of the channel regions.<H electronic, apparatus, Electro, optical, 7161193.html, Patent, pto, 7161193

Title: Electro-optical device and electronic apparatus

Abstract: There is provided an electro-optical device including, above a substrate, data lines extending in a first direction, scanning lines extending in a second direction and intersecting the data lines, pixel electrodes and thin film transistors disposed so as to correspond to intersection regions of the data lines and the scanning lines; and storage capacitors electrically connected to the thin film transistors and the pixel electrodes, the thin film transistors including semiconductor layers having channel regions which extend in a longitudinal direction and channel adjacent regions which extend further from the channel regions in the longitudinal direction, and the scanning lines including light-shielding parts disposed at sides of the channel regions.

Patent Number: 7,161,193 Issued on 01/09/2007 to Kawata, et al.

Inventors: Kawata; Hidenori (Chino, JP), Tsunekawa; Yoshifumi (Chino, JP), Hayashi; Tomohiko (Kokubo, JP)
Assignee: Seiko Epson Corporation (Tokyo, JP)

Appl. No.: 11/115,139

Filed: April 27, 2005

Foreign Application Priority Data


Oct 31, 2002 [JP]			2002-318624
Sep 12, 2003 [JP]			2003-321783

Current U.S. Class: 257/184 ; 257/187; 257/225; 257/232; 257/258; 257/292; 257/296

Current International Class: H01L 31/0328 (20060101)

References Cited [Referenced By]

U.S. Patent Documents


6610997	August 2003	Murade
6621546	September 2003	Yang et al.
6809338	October 2004	Murade
6850292	February 2005	Murade
2001/0029070	October 2001	Yamazaki et al.
2002/0008240	January 2002	HIrabayashi et al.

Foreign Patent Documents


A-10-197897	Jul., 1998	JP
A-2001-249625	Sep., 2001	JP
A-2001-281684	Oct., 2001	JP
2001-311964	Nov., 2001	JP
A-2001-330857	Nov., 2001	JP
A-2001-356371	Dec., 2001	JP
2002-090721	Mar., 2002	JP
A-2002-149087	May., 2002	JP
A 2002-156652	May., 2002	JP
A-2002-158360	May., 2002	JP
A2002-215064	Jul., 2002	JP
A-2002-244155	Aug., 2002	JP

Primary Examiner: Louie; Wai-Sing
Attorney, Agent or Firm: Oliff & Berridge, PLC

Parent Case Text

This is a Continuation of application Ser. No. 10/693,963 filed Oct. 28, 2003. The entire disclosure of the prior application is hereby incorporated by reference herein in its entirety.

Claims

What is claimed is:

1. An electro-optical device comprising, above a substrate: a substrate; a pixel electrode; a data line extending in a first direction; a thin film transistor including a semiconductor layer having a channel region that extends in a longitudinal direction; a storage capacitor electrically connected to the thin film transistor and the pixel electrode, the storage capacitor including a fixed capacitance line disposed between the pixel electrode and the data line at a position that overlaps the thin film transistor in plan view, the fixed capacitance line having a light shielding property that shields the thin film transistor from incident light; a gate electrode that overlaps with the channel region in plan view; a scanning line extending in a second direction and intersecting the data line, the scanning line being located in between the substrate and the channel; an insulation layer that separates the gate electrode from the scanning line; and contact holes that penetrate through the insulation layer to bring the gate electrode into electrical connection with the scanning line, the contact holes being disposed at sides of the channel region.

2. The electro-optical device according to claim 1, wherein the scanning line has a light shielding property.

3. The electro-optical device according to claim 1, wherein the scanning line includes a main-body part extending in a direction that intersects the longitudinal direction.

4. The electro-optical device according to claim 1, further comprising an upper light-shielding film at least covering the channel region of the thin film transistor from the upper side, at least a part of the upper light-shielding film being formed in a concave shape in a cross section perpendicular to the longitudinal direction of the channel region.

5. The electro-optical device according to claim 1, the scanning line including a light-shielding film containing metal or alloy.

6. The electro-optical device according to claim 1, wherein the fixed capacitance line extends in the second direction and being made of a multi-layered film including a low-resistive film.

7. The electro-optical device according to claim 1, the pixel electrode being electrically connected to other layers of a laminated structure through at least one of a titanium simple substance, a tungsten simple substance, a compound of titanium and tungsten, or a stack thereof.

8. The electro-optical device according to claim 7, wherein the laminated structure includes: interlayer insulating film provided as bases of the pixel electrodes, a contact hole formed in the interlayer insulating film to electrically connect the pixel electrodes thereto, and film formed at, at least an inside surface of the contact hole and a lower layer of the pixel electrodes, the film including a titanium simple substance, a tungsten simple substance, a compound of titanium or tungsten, or a stack thereof.

9. The electro-optical device according to claim 1, wherein the data line is formed of the same film as one of a pair of electrodes of the storage capacitor.

10. The electro-optical device according to claim 1, further comprising: relay layers as a part of a laminated structure, the relay layers electrically connecting the pixel electrode to one of a pair of electrodes of the storage capacitor.

11. The electro-optical device according to claim 10, wherein the shielding layer is formed of the same film as the relay layer.

12. The electro-optical device according to claim 1, at least some elements of the scanning line, the data line, a pair of electrodes of the storage capacitor constitute an embedded light-shielding film in the laminated structure.

13. The electro-optical device according to claim 1, wherein the scanning lines includes: a metal layer that contains a high-melting-point metal simple substance or a metal compound, and a barrier layer that is made of a high-melting-point and oxygen-free metal or a metal compound laminated on at least one surface of the metal layer.

14. The electro-optical device according to claim 13, wherein the metal layer includes a light-shielding metal layer and a light-absorbing metal layer, the light-absorption metal layer facing the thin film transistor.

15. The electro-optical device according to claim 13, further comprising another barrier layer, the metal layer being interposed between the barrier layer and the other barrier layer.

Description

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention relates to a technical field of an active-matrix-type electro-optical device, and more particular, technical fields of an electro-optical device having a structure where a thin film transistor (Thin Film Transistor; hereinafter referred to as "TFT") for switching a pixel is included in a laminated structure on a substrate, a method for manufacturing the same, and an electronic apparatus having the same as a light valve. The present invention also relates to a technical field of an electrophoresis device, such as an electronic paper, an EL (electroluminescent) device, and a device using an electron emission element (a field emission display and a surface-conduction electron-emitter display).

2. Description of Related Art

In an active-matrix-type electro-optical device, when incident light is exposed to a channel region of a pixel switching TFT provided in each pixel, excitation due to light causes light-leakage current so that properties of the TFT are changed. Particularly, in an electro-optical device for a light valve of a projector, because the intensity of incident light is very high, it is important to shield a channel region or peripheral region of the TFT from incident light.

Therefore, in the related art, such channel regions or peripheral regions are formed of light-shielding films defining opening of each pixel provided at a counter substrate, or data lines which are made of metal film such as Al (aluminum) or the like and pass over TFTs on a TFT array substrate. Further, light-shielding films made of high-melting-point metal or the like may be sometimes provided also under the TFTs above the TFT array substrate.

As described above, when light-shielding films are provided below the TFT, back side reflected light from a TFT array substrate or returning light, such as transmitted light transmitting through a prism from another electro-optical device, when a plurality of electro-optical device and prisms constitute one optical system, can be in advance prevented from being incident on the TFT of the electro-optical device.

However, there are the following problems with regard to each light-shielding technique described above. That is, first, according to a technique that a light-shielding film is formed on a counter substrate or a TFT array substrate, because the light-shielding film is separated through, for example, a liquid crystal layer, an electrode, an interlayer insulating film or the like far apart from the channel region in three dimensions, it is not sufficiently shielded from light incident between them at an angle. Particularly, in a small-sized electro-optical device used as a light valve of a projector, because incident light is a light beam obtained by wringing light from a light source through a lens, and includes unnegligible slant-incident component, for example, 10% slant-incident components at ten to fifteen angles from a vertical direction with respect to a substrate, being insufficiently shielded from such slant-incident light may be practically problematic.

In addition, light, which travels from a region free of light-shielding film to an electro-optical device, reflects onto a top surface of a substrate, top surfaces of light-shielding films formed on the substrate, or bottom surfaces of data lines, that is, inside surfaces of sides adjacent to channel regions. Sometimes, multi-reflected light, which is obtained by reflecting such reflected light onto a top surface of the substrate or inside surfaces of the light-shielding films or data lines again, may finally arrive onto channel regions of a TFT.

Particularly, as high precision of electro-optical device or fine pixel pitch is facilitated to meet recent, general requirements of high-quality display image, or light intensity of incident light is increased to display brighter image, it is more difficult to execute sufficient light shielding using various light-shielding techniques described above. Quality of display image may become worse due to flicker generated by characteristic change of the TFT transistor.

Further, although formation regions of light-shielding film may be broadened so as to enhance such light-resistant property, because enhanced aperture ratio of each pixel is basically requested to enhance brightness of display image, it is difficult to accomplish such enhancement of light-resistant property by broadening formation regions of the light-shielding films. Also, as described above, considering inside-reflected light or multi-reflected light due to light-shielding films, that is, lower light-shielding films under the TFT or upper light-shielding films above the TFT made of data lines and the like, optionally broadening the formation regions of light-shielding films will result in increase of such inside-reflected light or multi-reflected light, which is a difficult problem to be addressed.

SUMMARY OF THE INVENTION

Accordingly, the present invention provides an electro-optical device capable of suppressing generation of light leakage current and displaying high-quality image free of flicker or the like by enhancing light-shielding performance of the TFT to the semiconductor layer. The present invention provides an electronic apparatus including such an electro-optical device.

In order to achieve the above, the electro-optical device according to an aspect of the present invention includes, above a substrate, data lines extending in a first direction, scanning lines extending in a second direction and intersecting the data lines, pixel electrodes and thin film transistors provided so as to correspond to intersection regions of the data lines and the scanning lines, and storage capacitors electrically connected to the thin film transistors and the pixel electrodes. The thin film transistors include semiconductor layers having channel regions which extend in a longitudinal direction and channel adjacent regions which extend further from the channel regions in the longitudinal direction, and the scanning lines include light-shielding parts disposed at sides of the channel regions.

According to an aspect of the present invention, due to the light-shielding parts, incident light and returning light, which travel at an angle onto the surface of the substrate, and the slant light, such as the inside-reflected light and the multiple-reflected light based on these, can be at least partially prevented from entering into the channel regions.

In an aspect of an electro-optical device according to the present invention, the scanning lines preferably include main body parts extending in a direction intersecting the longitudinal direction and having gate electrodes of the thin film transistors overlapping the channel region in plan view, and horizontal protrusions protruding from the main body parts in the longitudinal direction at sides of the channel adjacent regions in plan view and constituting the light-shielding parts.

According to the above electro-optical device, the scanning lines include the horizontal protrusions protruding along the channel regions at the sides of the channel regions from the main body parts which include gate electrodes of the thin film transistors in plan view. Therefore, the incident light and the returning light, which travel at an angle with respect to the surface of the substrate and the slanted light, such as the inside-reflected light and the multiple-reflected light based on the incident light and the returning light, can be at least partially prevented from entering into the channel regions and the channel adjacent regions, due to light absorption and light reflection, particularly by the horizontal protrusions, as well as by the main body parts which include the gate electrodes among the scanning lines. At this time, particularly, since the light shielding is performed by the horizontal protrusions which are provided at positions where the interlayer distance from the channel adjacent regions is very short, that is, at the interlayer positions separated by the thickness of the gate insulating films, it is possible to further effectively perform the light-shielding.

For example, on the substrate, in a case wherein the lower light-shielding films are provided at the lower sides of the thin film transistors, since the construction that the channel adjacent regions or the channel regions are interposed between the lower light-shielding films interlayer distance of which is relatively short and the main body parts or the horizontal protrusions which function as light-shielding films can be obtained, it is possible to obtain the excellent light-shielding performance for the slanted light.

As a result, according to the above aspect, since the light-resistant property can increase, it is possible to efficiently control the switching of the pixel electrodes by the thin film transistors light leakage current of which is reduced under such a severe condition wherein strong incident light or returning light enters, and finally, to display images with high brightness and high contrast.

In one aspect of an electro-optical device according to an aspect of the present invention, it is preferable that the main body parts and the horizontal protrusions be formed of the same film in one body.

According to the above aspect, in the manufacturing process of the electro-optical device, since the light-shielding protrusions can be formed by the process of forming the scanning lines with the main body parts, any additional process is not necessary to form the protrusions. Therefore, it is possible to facilitate simplification of the laminated structure and the manufacturing process.

Furthermore, in an aspect that the horizontal protrusions are provided, it is preferable that the horizontal protrusions protrude at source side and drain side at every channel region in plan view.

According to the above aspect, by these protrusions, it is possible to enhance the light-shielding performance for the slanted light that enters from various directions three-dimensionally. Further, a total of four horizontal protrusions may be provided at the source side, the drain side, and both sides thereof at every thin film transistors.

In another aspect of the electro-optical device of the present invention, the thin film transistors include semiconductor layers having channel regions which extend in longitudinal direction, the electro-optical device may include upper light-shielding films which cover at least the channel regions of the thin film transistors from the upper side, and at least a part of the upper light-shielding films is formed in a concave shape on the cross section which is perpendicular to the longitudinal direction of the channel region, as viewed from the channel regions.

According to the above aspect, the upper light-shielding films covering at least the channel regions from the upper sides are provided, and at least a part of the upper light-shielding films is formed in a concave shape on the cross section perpendicular to the longitudinal direction of the channel region, as viewed from the channel regions. In other word, the lower side has a concave shape. For the reason, in comparison to the case that the upper light-shielding films are flat, the incident light which travels at an angle with respect to the surface of the substrate and the slanted light, such as the inside-reflected light and the multiple-reflected light based on the incident light and the returning light, can be prevented more effectively from entering from the slanted upper side finally into the channel regions by the upper light-shielding films.

For example, in a case wherein the lower light-shielding films are provided at the lower side of the thin film transistors above the substrate, since the construction that the channel regions are interposed between the lower light-shielding films and the upper light-shielding films, it is possible to obtain the excellent light-shielding performance for the slanted light. At that time, at least a part of the lower light-shielding films may be formed in a concave shape on the cross section, which is perpendicular to the longitudinal direction of the channel region, as viewed from the channel regions, contrary to the unevenness of the aforementioned upper light-shielding films.

As a result, in accordance with the aspect, since the light-resistant property can increase, it is possible to efficiently control the switching of the pixel electrodes by the thin film transistors leakage current of which light is reduced under such a severe condition that strong incident light or returning light enters, and finally, to display images with high brightness and high contrast.

In another aspect of the electro-optical device of the present invention, the thin film transistors include semiconductor layers having channel regions which extend in the first direction. The scanning lines include main line portions including gate electrodes of the thin film transistors which face the channel regions with gate insulating films interposed therebetween and extending in the second direction which intersects the first direction in plan view, and surroundings parts which extend to surround the semiconductor layers from the main line portions at positions which are separated from the channel regions by a predetermined distance in the second direction in plan view.

According to the above aspect, the scanning lines include surroundings parts which extend to surround the semiconductor layers from the main line portions at positions which are separated from the channel regions by a predetermined distance in the second direction in plan view. Therefore, the incident light and the returning light, which travel to the surface of the substrate and the slanted light, such as the inside-reflected light and the multiple-reflected light based on the incident light and the returning light, can be at least partially prevented from entering into the channel regions and the channel adjacent regions, due to light absorption and reflection, particularly by the surrounding portions, as well as by the main body parts which include the gate electrodes among the scanning lines. At this time, particularly, since the light-shielding is performed by the surrounding portions which are located at the positions where the interlayer distance from the channel regions or the channel adjacent regions is very short, that is, at the interlayer positions separated by the thickness of the gate insulating films and also the surrounding portions can shield the slanted light in any direction, it is possible to further effectively perform the light-shielding.

As a result, according to the present aspect, since the light-resistant property can increase, it is possible to efficiently control the switching of the pixel electrodes by the thin film transistors light leakage current which is reduced under such a severe condition that strong incident light or returning light enters, and finally, to display image with high brightness and high contrast by the present invention.

In addition, in consideration of the technical effects, the construction of "surround the semiconductor layer in plan view" has wider concepts including the construction that the surrounding portions are formed to have slight disconnection parts around the lower side of the channel regions around the semiconductor layers in plan view, the construction that the surrounding portions are intermittently formed, or the construction that the surrounding portions are sporadically formed in an island shape, other than the construction that the surrounding portions are formed to extend continuously around the semiconductor layers in plan view.

In the aforementioned aspect, particularly, it is preferable that the scanning lines further include the vertical protrusions protruding from the main line portions in the direction perpendicular to the substrate at the positions which are separated from the channel regions by a predetermined distance in the second direction.

According to the above aspect, because the main line portions include the vertical protrusion protruding in the direction perpendicular to the substrate, the channel regions are three-dimensionally covered by the main line portions that include the vertical protrusions. As a result, the light-shielding performance can be increased. Particularly, when a so-called top gate type in which the scanning lines are located at the upper sides of the channel regions, the construction that the channel regions are three-dimensionally covered by the main line portions including the vertical protrusions protruding from the upper sides is obtained. In addition, the predetermined distance associated with the surrounding portions and the predetermined distance associated with the vertical protrusions may be equal to or different from each other.

In addition, in the aspect that the aforementioned surrounding portions are provided, it is preferable that the scanning lines further include vertical protrusions protruding from the surrounding portions in the direction perpendicular to the substrate.

According to the above aspect, since the channel regions can be three-dimensionally covered by the vertical protrusions of the main line portions and/or the vertical protrusion of the surrounding portions, it is possible to further enhance the light-shielding performance. Particularly, in case of a so-called "top gate type" in which the scanning lines are located at the upper side of the channel regions, the construction that the channel regions are three-dimensionally covered by the main line portions and the surrounding portions including the vertical protrusions from the upper sides is obtained. In addition, these vertical protrusions may protrude consecutively or separately.

In another aspect of the electro-optical device of the present invention, the thin film transistors include semiconductor layers having channel regions which extend in the first direction, and the scanning lines include main line portions including gate electrodes of the thin film transistors which face the channel regions with gate insulating films interposed therebetween and extending in the second direction which intersects the first direction in plan view, and vertical protrusions which protrude downward from the main line portions at positions which are separated from the channel region by a predetermined distance in the second direction in plan view.

According to the above aspect, the scanning lines include the vertical protrusions which protrude downwardly from the main line portions at positions which are separated from the channel region by a predetermined distance in the second direction in plan view. Therefore, the incident light and the returning light which travel to the surface of the substrate and the slanted light, such as the inside-reflected light and the multiple-reflected light based on the incident light and the returning light can be three-dimensionally reduced or prevented from entering into the channel regions and the channel adjacent regions particularly by the protrusions as well as by the main body parts which include the gate electrodes among the scanning lines, and the channel regions and the channel adjacent regions can be three-dimensionally shielded by the main line portions and the protrusions at positions in the vicinity of the channel regions or the channel adjacent regions, it is possible to further effectively perform the light-shielding.

As a result, in accordance with the aspect, since the light-resistant property can increase, it is possible to effectively control the switching of the pixel electrodes by the thin film transistors light leakage current which is reduced under such a severe condition that strong incident light or returning light enters, and finally, to display images with high brightness and high contrast.

In the aspect that the aforementioned vertical protrusions are provided, particularly, it is preferable that lower light-shielding films that at least cover the channel regions from the lower side can be further provided and the vertical protrusions have front ends which are contacted to the lower light-shielding films.

In accordance with the construction, the construction that the channel adjacent regions or the channel regions are interposed between the lower light-shielding films interlayer distance of which is relatively short and the main body parts or the surrounding portions which function as light-shielding films can be obtained. In addition, the space between the lower light-shielding films and the main body parts and the surrounding portions of the scanning lines, where the channel adjacent regions or the channel regions exist, becomes a partially closed space by the protrusions. For the reason, it is possible to obtain very high light-shielding performance on the slanted light which is slanted in any direction.

Furthermore, in accordance with the aspect, for example, it is possible that the scanning lines and the gate electrodes of the thin film transistors are not formed of the same layer, but the gate electrodes and the scanning lines are formed in different layers, and some of the scanning lines are used for the lower light-shielding films in such aspect. Namely, in this case, the lower light-shielding films have the additional function as the scanning lines. In addition, as another aspect, it is possible that the gate electrodes and the scanning lines are formed in the same layer, while the lower light-shielding films have the function as the scanning lines. In this case, two scanning lines are provided parallel to any one of thin film transistors and redundancy structure is provided to the scanning lines. By doing so, even though any one of scanning lines has a failure, such as disconnection, the other scanning line can be used, so that an advantage of further increasing the reliability can be obtained.

In addition, in the above case that the lower light-shielding films have the additional function as scanning lines, it is necessary that the lower light-shielding films are formed in a stripe shape to correspond to the rows of the thin film transistors arranged in a matrix.

On the other hand, it is preferable that the lower light-shielding films, which at least cover the channel regions from the lower side, be further provided, and the vertical protrusions do not contact the lower light-shielding films.

In accordance with the construction, the construction that the channel adjacent regions or the channel regions are interposed between the lower light-shielding films interlayer, the distance of which is relatively short, and the main body parts or the surrounding portions, which function as light-shielding films, can be obtained. In addition, the space between the lower light-shielding films and the main body parts and the surrounding portions of the scanning lines, where the channel adjacent regions or the channel regions exist, becomes a partially closed space by the protrusions. For such a reason, it is possible to obtain very high light-shielding performance on the slanted light which is slanted in any direction.

In addition, in a case wherein the construction in which the lower light-shielding films and the scanning lines do not contact with each other is employed, bad effect due to not the electrical conductivity but the potential variation of the lower light-shielding films, for example, the bad effect on the thin film transistors can be reduced or prevented in advance.

In another aspect of the electro-optical device according to the present invention, the thin film transistors include semiconductor layers having channel regions which extend in the first direction, the scanning lines include main line portions including gate electrodes of the thin film transistors which face the channel regions with gate insulating films interposed therebetween and extending in the second direction which intersects the first direction in plan view, and the main line portions include inside-groove parts which are provided inside grooves which are engraved in the substrate and cover at least a part of the channel regions from the sides.

According to the above aspect, the scanning lines include the main line portions which extend in the second direction in plan view. Herein, particularly, the inside-groove parts which are provided inside groove among the main line portions at least partially cover the channel regions from the sides. Therefore, the incident light, which travels at an angle with respect to the surface of the substrate, the returning light, which particularly travels at an angle with respect to the rear surface, and the slanted light, such as the inside-reflected light and the multiple-reflected light based on the incident light and the returning light can be partially prevented from entering into the channel regions and the channel adjacent regions, due to light absorption and reflection by the inside-groove parts. Like this, by increasing the light-resistant property, it is possible to efficiently control the switching of the pixel electrodes by the thin film transistors light leakage current of which is reduced under such a severe condition that strong incident light or returning light enters, and thus, it is possible to display images with high brightness and high contrast.

In addition, since the main line portions of the scanning lines include the inside-groove parts, by increasing the cross sectional areas of the inside-groove parts at the cross section perpendicular to the second direction and the cross sectional areas of the outside-groove parts which are located outside the grooves, it is possible to reduce the wire resistance of the scanning lines. Like this, by reducing the wire resistance of the scanning lines, it is possible to reduce the occurrence of the crosstalk or flicker, etc., due to the signal delay of the scanning signals, and as a result, finally, it is possible to display images with high quality, while facilitating the high accuracy and miniaturization of the pixel pitch in the electro-optical device. As a result, it is possible to display images with high brightness and high quality in accordance with the present invention.

In addition, in the present invention, the grooves in which the main line portions of the scanning lines are at least partially provided may be directly engraved in the substrate like the above case, or may be engraved in the base insulating films which are laminated on the substrate.

In another aspect of the electro-optical device of the present invention, the thin film transistors include semiconductor layers having channel regions which extend in the first direction. The scanning lines include main line portions including gate electrodes of the thin film transistors which face the channel regions with gate insulating films interposed therebetween and extending in the second direction which intersects the first direction in plan view. The main line portions include inside-groove parts which extend in the second direction and are provided inside grooves which are engraved in the substrate and outside-groove parts which extend in the second direction and are provided outsides the grooves.

According to the above aspect, the scanning lines include the main line portions which extend in the second direction in plan view. Herein, particularly, since the main line portions include the inside-groove parts and the outside-groove parts which extend in the second direction, respectively, it is possible to reduce the wire resistance of the scanning lines in accordance with the total area of the inside-groove parts and the outside-groove parts on the cross section perpendicular to the second direction. For example, in consideration of a certain restriction in the allowable step difference on the surface of the substrate which defines the thickness of the layers of the electro-optical materials, such as liquid crystal in relation to the operational failure of the electro-optical materials, such as disorder of the liquid crystal, in comparison with the related art scanning lines which are formed on the flat surface or the scanning lines which are completely buried within the grooves, the construction of the present invention in which the cross sectional area of the scanning lines can increase over the total thickness in the laminated structure on the substrate is very advantageous in practice.

Like this, by reducing the wire resistance of the scanning lines, it is possible to reduce the occurrence of the cross talk or flicker, etc., due to the signal delay of the scanning signals, and as a result, and finally, it is possible to display images with high quality while facilitating the high accuracy and miniaturization of the pixel pitch in the electro-optical device.

In addition, in the present invention, the groove in which the main line portions of the scanning lines are at least partially provided may be directly engraved in the substrate like the above case, or may be engraved in the base insulating films which are laminated on the substrate.

As described above, the light-shielding can be performed on the semiconductor layer by particular constituents, for example, vertical protrusions, surrounding portions, etc., being provided to the scanning lines as described above, particularly, it is preferable that the scanning lines include light-shielding films containing metals or alloys.

According to the above aspect, the scanning lines include the light-shielding films which are made of metals or alloys, and more specifically, for example, a metal single substance, a metal alloy, a metal silicide, a poly silicide including at least one of high melting point metals such as Ti (titan), Cr (chromium), W (tungsten), Ta (tantalum), and Mo (molybdenum), Pb (lead), etc., or laminated structure thereof. Therefore, by the main body parts and the protrusions made of these light-shielding films, it is possible to further enhance the light-shielding performance over the slanted light in the channel regions or the channel adjacent regions.

However, even in a case where the scanning lines are formed of not such light-shielding films but polysilicon films, etc., the light-shielding performance can be obtained by the light-absorbing property.

In another aspect of an electro-optical device according to the present invention, one of a pair of electrodes constituting each of the storage capacitors constitutes a part of a capacitive line formed along the second direction, and the capacitive line is made of a multi-layered film including a low-resistive film.

According to such aspect, first, one of a pair of electrodes (hereinafter, referred to as "one side electrode") constituting storage capacitor constitutes a part of capacitive line formed along a second direction, that is, formation direction of scanning lines. By doing so, for example, in order to hold the one side electrode a constant potential, each capacitive line may be connected to constant potential source without providing individually conductive materials for holding a constant potential. Thus, according to the present exemplary embodiment, it is possible to facilitate simplification of the manufacturing process or low manufacturing cost.

Also, in the present aspect, particularly, the capacitive lines are formed of multi-layered films including low-resistive film. In such configuration, it is possible that the capacitive line carries out the function as constant-potential side capacitive electrode of corresponding capacitive line and other functions. Particularly, because corresponding multi-layered film includes low-resistive film, that is, lower resistive material than related art polysilicon or WSi, for example, metal simple substance such as aluminum, copper, chromium, or materials including them, or the like, it is possible to accomplish high conductivity. And, due to the high conductivity accomplishment, narrowness of the capacitive line, that is, narrowness of the storage capacitor can be obtained in the present aspect without specific restriction. Thus, the present aspect greatly contributes to facilitate enhancement of aperture ratio. In other words, it is possible to reduce or prevent cross talks or sticking due to high resistivity which originated from narrowness of capacitive line in a the related art.

Also, because the capacitive line of the present aspect is formed of multi-layered film, including low-resistive film described above, it is possible to add films formed of other materials for realizing light-shielding property reduce or prevent light-incidence onto thin film transistors to the low-resistive film as constituents of the capacitive line.

In addition, when the capacitive line of the present invention is formed of multi-layered films, it is possible to stabilize function as a storage capacitor. That is, for example, considering only low resistance described above, it is sufficient to form the capacitive line using a single layer of such material. But, the storage capacitor may insufficiently function as a condenser. However, in an aspect of the present invention, as described above, the capacitive line is formed of double or more layered films, although the first layer is formed compensatingly of a material for specific function, because other layers can be formed of materials for functioning as a storage capacitor, the above-described problems are addressed.

Also, in the present invention, because it is possible to facilitate multiple functions described above in the capacitive lines, degree of design freedom for an electro-optical device can also be enhanced.

In another an aspect of electro-optical device according to the present invention, the capacitive line includes an upper layer formed of the low-resistive film and a lower layer having light-absorption property.

According to such aspect, the capacitive line can be facilitated to behave like the multiple functions described below. First, because an upper layer of the capacitive line includes the low-resistive film, for example, when light is incident on the upper layer, it is possible to previously reduce or prevent the light, which is reflected on the surface of the low-resistive film, from directly entering the thin film transistor. Such a possibility is based on a fact that the corresponding materials have generally high optical reflectivity.

On the other hand, because the capacitive line is formed of light-absorbable material, such as polysilicon, it is possible to previously reduce or prevent so-called dim light, which is obtained as a result of being incident on the electro-optical device and then being reflected from the surface of the low-resistive film or a bottom surface of the data line, from entering onto a thin film transistor. Namely, because whole or a part of such dim light is absorbed into the lower layer of the capacitive line, it is possible to reduce the possibility that the dim light may reach the thin film transistor.

Also, in an aspect of the present invention, because it is premised that the capacitive line is "formed in the shape of multi-layered film", for example, although aluminum is positioned on the capacitive line and polysilicon is positioned under the capacitive line, it is needless to say that a film of other material can be positioned above the layer of aluminum or below the layer of polysilicon, also that films of other material can be positioned between the layers of aluminum and polysilicon. Also, it is of course acceptable that aluminum, polysilicon, and aluminum are structured from the top in order.

In another aspect of an electro-optical device according to the present invention, the very low-resistive film is made of aluminum.

According to such an aspect, because aluminum is a low-resistive material, the above-described effect is more reliably obtained. In addition, resistance of aluminum is about 1/100 of that of polysilicon or WSi.

Further, according to the present configuration that the capacitive line includes aluminum, it is possible to obtain the following working effect. In the related art, because the capacitive line is formed of the polysilicon simple substance or WSi, bent property of such material causes great stress in an interlayer insulating film formed on the capacitive line. But, there is no such problem in the present invention. That is, in the related art, because the stress causes a restriction about thickness of the interlayer insulating film, if the thickness thereof is set so thin, the film is sometimes broken due to the corresponding stress. In the present aspect, it is possible to form thinner interlayer insulating film than that of the related art. As a result, it is possible to facilitate miniaturization of an electro-optical device as a whole.

In an aspect of an electro-optical device according to the present invention, the pixel electrode is electrically connected to different layers in the laminated structure through a titanium simple substance, a tungsten simple substance, a compound of titanium or tungsten, or a stack of them.

According to such an aspect, it is possible to electrically connect the different layers (i.e., at least one of a pair of electrodes constituting storage capacitor, or relay layer described below) in the laminated structure with the pixel electrode preferably. And, because the pixel electrode is formed of transparent conductive material, such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), or the like, if connected to aluminum, electrical erosion is produced. As a result, preferable electrical connection is not realized because of disconnection of aluminum or insulation due to formation of alumina. But, in the present aspect, because the pixel electrode is electrically connected to different layers in the laminated structure through titanium simple substance, a tungsten simple substance, a compound of titanium or tungsten, or a stack of them, the above-described inconvenience does not occur.

In such an aspect, an interlayer insulating film arranged as a base of the pixel electrode constitutes a part of the laminated structure. A contact hole is formed in the interlayer insulating film to electrically connect with the pixel electrode, and a film including a titanium simple substance, a tungsten simple substance, a compound of titanium or tungsten, or a stack of them is preferably formed on at least inside surface of the contact hole.

According to such configuration, first, without worry about the above-described electrical erosion, it is possible to electrically connect the pixel electrode with the other layers. Also, in the present configuration, because a contact hole is interposed between the pixel electrode and the other layers, it is possible to facilitate an enhancement of a proper arrangement for the layers in the laminated structure or degree of layout freedom. In other words, as each component of the laminated structure is suitably arranged, and more concretely, is arranged within light-shielding region so that broadening of optical-transmittance region, namely, the above-described object can also be accomplished more preferably, it greatly contributes to realization and holding of high aperture ratio.

Further, in the present configuration, because a film including titanium simple substance, a tungsten simple substance, a compound of titanium or tungsten, or a stack of them is formed on at least an inside surface of the contact hole, it is possible to previously reduce or prevent light leakage due to the contact hole. That is, as a result of absorbing or reflecting light, it is possible to reduce or prevent the light from traveling through void part of the contact hole. As a result, light leakage on image hardly happens. Also, based on the same reason, it is possible to enhance light-resistance of the thin film transistor and the semiconductor layer. As a result, when light is incident on the semiconductor layer, it is possible to reduce or prevent light leakage current, and thereby, previously reduce or prevent flicker on image. As described above, according to the present configuration, it is possible to display higher quality image.

In another aspect of the electro-optical device according to the present invention, each of the data lines is formed of the same film as one of a pair of electrodes which constitute each of the storage capacitors.

According to the above aspect, each data line and one electrode in a pair of electrodes which constitute each of the storage capacitors are made of the same film, in other words, formed on the same layer, or formed in the same manufacturing process. By doing so, it is not necessary to provide both of each of the data lines and one electrode on separate layers and to separate them by interlayer insulating films. Thus, it is possible to avoid a highly laminated structure. At this point, this aspect of the present invention is very advantageous in that the laminated structure includes the shielding layers formed between the data lines and the pixel electrodes, and thus, a highly laminated structure which has an altitude increase is expected. The reason for such an advantage is that, excessively multi-layered structure obstructs easy manufacturing or high manufacturing yield. In addition, even though the data lines and the one electrode of a pair of the electrodes are formed at the same time, by an appropriate patterning process on the aforementioned films, it is possible to facilitate the insulation between them, and no particular problem occurs with respect to this point.

In addition, conversely, as apparent from the description of the aspect, in the present invention, it is not always necessary to form each of the data lines and the one electrode of a pair of electrodes which constitute each of the storage capacitors as the same film. In other words, they may be separately formed in the different layers.

In another aspect of the electro-optical device according to the present invention, the electro-optical device further includes relay layers, as parts of a laminated structure, to electrically connect each of the pixel electrodes to at least one of a pair of electrodes which constitute each of the storage capacitors.

According to the above aspect, the one electrode of a pair of electrodes of each of the storage capacitor and the pixel electrodes which constitute some portions of the laminated structure, respectively, are electrically connected to the relay layer which constitutes some portions of the laminated structure. Specifically, such connection may be performed through contact holes. By doing so, for example, the relay layers according to the present invention are formed of a two-layered structure, while the upper layer is made of a material which is very compatible with ITO as an example of a transparent conductive material which is generally used as a material of the pixel electrode and the lower layer is made of a material which is compatible with one electrode of a pair of electrodes which constitute each of the storage capacitor. Like this, since the relay layer can employ such a flexible construction, it is possible to further suitably implement the application of voltage to the pixel electrodes or the potential holding in the pixel electrodes.

Also, in relation to proper arrangement of the pixel electrode and the storage capacitor, it is desirable to provide such "relay layer". That is, according to the present aspect, because relay layers and storage capacitors can be arranged so as to broaden light-transparent region as much as possible, very higher aperture ratio can be obtained.

In the aspect, particularly, it is preferable that the relay layers include an aluminum film and a nitride film.

In accordance with the construction, in a case wherein the pixel electrodes include, for example, ITO, if the ITO and the aluminum are directly contacted, electrical erosion occurs between them, and thus, the disconnection of the aluminum or the insulation due to occurrence of alumina occurs, so that it is not desirable. Therefore, in the above aspect, the ITO does not directly contact the aluminum, but the ITO contacts a nitride film, for example, a titanium nitride film, so that it is possible to implement electrical connection to the storage capacitors as well as the pixel electrodes and the relay layer. Like this, the construction provides an example of the aforementioned "well-compatible material".

Furthermore, since the nitride film, such as a silicon nitride film or a silicon oxide film, has an excellent function of reducing or preventing water from permeating or diffusing, it is possible to reduce or prevent water from permeating the semiconductor layers which constitute the thin film transistors in advance. In the above aspect, since the relay layers include the nitride films, it is possible to obtain the aforementioned functions, and thus, it is possible to minimize the occurrence of the problem in that the threshold voltage of the thin film transistors greatly increase.

Furthermore, particularly, in an aspect that the relay layers are provided, it is preferable that the shielding layers be formed of the same film as the relay layers.

In the construction according to the above aspect, since the relay layers and the shielding layers are formed of the same film, both constituents can be formed at the same time, so that it is possible to facilitate simplification of the manufacturing process or to lower manufacturing cost as much.

In another aspect, in which the construction according to the above aspect combines with the aforementioned aspect in that the data lines and the one electrode of a pair of electrodes which constitute each of the storage capacitor are formed of the same film, the arrangement of the data lines, the storage capacitors, the relay layers, and the pixel electrodes, particularly, the laminating order, etc., becomes preferable, so that it is possible to further effectively obtain the aforementioned functions and effects.

Further, particularly, in another aspect in which the construction according to the above aspect combines with the construction that the relay layers include the nitride film, the shielding layers also include the nitride films. Therefore, it is possible to further obtain the water permeation reducing or preventing function on the semiconductor layers of the thin film transistors over the surface of the substrate as described above. Accordingly, it is possible to further effectively obtain the function and effect of the long-term maintenance of the thin film transistor.

In addition, as is apparent from the description of the above aspect, in the present invention, it is not always necessary to form the shielding layers and the relay layers as the same film. In other words, they may be separately formed in the different layers.

In another aspect of the electro-optical device according to the present invention, at least a part of the scanning line, the data line, a pair of electrodes of the storage capacitor, and the shield layer is formed of light-shielding material, and the portion is in the laminated structure and constitutes an embedded light-shielding film.

According to such an aspect, each component constituting the stacked structure on a substrate is formed of light-shielding material to form light-shielding film defining light-transparent region. As a result, because "an embedded light-shielding film" is provided on the substrate, light leakage current is generated by incident light on a semiconductor layer of a thin film transistor so that flicker on image can be previously prevented. That is, it is possible to enhance light-resistant property of the thin film transistor to the semiconductor layer. In addition, when the thin film transistor is formed in closest or closer layer to the substrate, because the scanning line, the data line, the storage capacitor, and the shield layer are formed above the thin film transistor, a light-shielding film including them can be called "upper light-shielding film".

Further, "light-shielding material" in the present aspect, for example, is made of metal simple substance including at least one of high-temperature metal such as Ti (titan), Cr (chromium), W (tungsten), Ta (tantalum), and Mo (molybdenum), etc., a metal alloy, a metal silicide, a poly silicide, stacked structure thereof, or the like. Also, such "light-shielding material" may contain aluminum (Al).

In addition, in the present aspect, particularly, although all of components preferably constitute "embedded light-shielding film", more preferably, at least two components extending in two directions intersecting each other constitute the "embedded light-shielding film" as a set. For example, when capacitive line is formed in a second direction where the scanning line extends and a part of the capacitive line becomes one of a pair of electrodes constituting the storage capacitor, it is desirable that the corresponding capacitive line and the data line are made of light-shielding material and constitute the "embedded light-shielding film". As a result, because the "embedded light-shielding film" has a shape of a lattice, it is possible to preferably arrange the pixel electrodes in a conventional matrix.

In another aspect of an electro-optical device according to the present invention, a light-shielding film provided in the light-shielding region is further included, and the light-shielding film includes a barrier layer including a metal layer made of high-melting-point temperature metal simple substance or metal compound, and an oxygen-free and high-melting-point temperature metal or a metal compound stacked on at least one side of the metal layer.

According to the present aspect, the following working effect can be obtained.

That is, although the light-shielding film is made of light-shielding material including Ti, Cr, W, or the like described above, in the related art, it has been proposed Ti having relatively excellent light-shielding property is used to form the light-shielding film. But, after forming the light-shielding film using Ti, when an insulating film or a thin film transistor is formed on the light-shielding film, if high-temperature process, such as annealing process of 500 degrees or more may be performed, chemical reaction is produced between the light-shielding film and an insulating film, such as SiO2 including an oxygen element, so that an oxide film can sometimes be formed. And, if such oxide film is formed, because the light-shielding property of Ti may decrease, although the relatively excellent Ti may be used, it is sometimes impossible to obtain sufficient light-shielding property.

But, in the present aspect, although the high-temperature process is performed after forming a light-shielding film, by an insulating film, such as SiO.sub.2 including an oxygen element and a barrier layer made of an oxygen-free and high-melting-point temperature metal or a metal compound of the light-shielding film, it is possible to reduce or prevent oxidation of the metal layer of the light-shielding film, and thereby to assure a light-shielding property of the light-shielding film.

Therefore, according to the present aspect, although a light-shielding film is formed to be narrow, it can be expected to excellently execute a light-shielding property. In other words, in the present aspect, it is needless to broaden the light-shielding film so as to reduce or prevent light incidence onto the thin film transistor or the semiconductor. Thus, the present aspect can play a big role in obtaining higher aperture ratio as one of the main objects of the present invention.

Also, the light-shielding film can be formed thinner than that of a related art light-shielding film using single WSi. As a result, it is possible to reduce the height difference between a region where the light-shielding film is formed and a region where the light-shielding film is not formed. For example, the metal layer may have a thickness of 30 to 50 nm, and the barrier layer may have a thickness of 10 to 100 nm.

In addition, as described above, the "light-shielding film" in the present aspect may be an "embedded light-shielding film"