LCD with relay layer connecting pixel electrode with storage capacitor that also covers the storage capacitor

• US 7,176,989 B2
• Filed: 10/28/2003
• Issued: 02/13/2007
• Est. Priority Date: 10/31/2002
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Shimizu, Yuichi, Takahara, Kenichi, Kurashina, Hisaki
• Primary Examiner(s): Schechter; Andrew
• Assistant Examiner(s): Vu; Phu
• Application Number:
  US10/694,019
• Publication Number:
  US 20040141097A1
• Time in Patent Office: 1,204 Days
• Field of Search: 349 38- 39, 349 43- 44, 349110-111, 349/29
• US Class Current: 349/39
• CPC Class Codes: G02F 1/136209 Light shielding layers, e.g. black matrix, incorporated in the active matrix substrate, e.g. structurally associated with the switching element
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer

Abstract

An electro-optical device including, above a substrate: data lines extending in a first direction, scanning lines extending in a second direction which intersects 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. Dielectric films which constitute the storage capacitors are made of a plurality of layers including different materials and one of the plurality of the layers is made of a material having a higher dielectric constant than those of the other layers.

Claims

1. An electro-optical device comprising, above a substrate:

a data line extending in a first direction;

a scanning line extending in a second direction which intersects the data line;

a pixel electrode and thin film transistor provided so as to correspond to an intersection region of the data line and the scanning line;

a storage capacitor electrically connected to the thin film transistor and the pixel electrode, dielectric films which constitute the storage capacitor being made of at least two layers including different materials and one of the at least two layers being made of a material having a higher dielectric constant than that of the other layer;

a relay layer that electrically connects the pixel electrode and the storage capacitor and that at least partially covers the storage capacitor to shade the storage capacitor from incident light; and

a light shielding layer provided between the data line and the pixel electrode, the light shielding layer being formed along the data line and having a width wider than the width of the data line, the light shielding layer being formed to cover the entire data line in plan view, the light shielding layer at least partially covering the storage capacitor.

2. The electro-optical device according to claim 1, the dielectric films being made of silicon oxide films and silicon nitride films.

3. The electro-optical device according to claim 1, the storage capacitor being formed above a semiconductor layer of the thin film transistor and below the pixel electrode.

4. The electro-optical device according to claim 1, a planarization process being performed on surfaces of an interlayer insulating film which is positioned beneath the pixel electrode.

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

6. The electro-optical device according to claim 1, the relay layer electrically connecting the pixel electrode to one of a pair of electrodes of the storage capacitor.

7. The electro-optical device according to claim 6, the light shielding layer and the relay layer having a multi-layer structure including a titanium nitride layer formed over an aluminum layer, the light shielding layer being formed from the same films as the relay layer.

8. The electro-optical device according to claim 1,

the shielding layer being made of transparent conducting materials and formed in a mat shape over the entire surface of the substrate.

9. The electro-optical device according to claim 1,

the thin film transistor including a semiconductor layer having a channel region which extends in a longitudinal direction and a channel adjacent region which extends in the longitudinal direction further from the channel region;

and

the scanning line including a main body part extending in a direction intersecting the longitudinal direction and having a gate electrode of the thin film transistor overlapping the channel region in plan view, and

a horizontal protrusion protruding from the main body part in the longitudinal direction at a side of the channel adjacent region in plan view.

10. The electro-optical device according to claim 1, the thin film transistor including a semiconductor layer having a channel region which extends in a longitudinal direction,

the electro-optical device further comprising

an upper light-shielding film covering at least 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 the cross section which is perpendicular to the longitudinal direction of the channel region as viewed from the channel region.

11. The electro-optical device according to claim 1,

the thin film transistor including a semiconductor layer having a channel region which extends in the first direction, and

the scanning line including a main line portion having a gate electrode of the thin film transistor which faces the channel region with a gate insulating film interposed therebetween and extending in the second direction which intersects the first direction in plan view, and

a surrounding portion extending to at least partially surround the semiconductor layer from the main line portion at a position which is separated from the channel region by a predetermined distance in the second direction in plan view.

12. The electro-optical device according to claim 1,

the thin film transistor including a semiconduetor layer having a channel region which extends in the first direction, and

the scanning line including a main line portion having a gate electrode of the thin film transistor which faces the channel region with a gate insulating film interposed therebetween and extending in the second direction which intersects the first direction in plan view, and

a vertical protrusion protruding downwardly from the main line portion at a position which is separated from the channel region by a predetermined distance in the second direction in plan view.

13. The electro-optical device according to claim 12, further comprising,

on the substrate, a lower light-shielding film which covers at least the channel region from the lower side,

the vertical protrusion contacting the lower light-shielding film at a front end thereof.

14. The electro-optical device according to claim 1,

the thin film transistor including a semiconductor layer having a channel region which extends in the first direction, and

the scanning line including a main line portion having a gate electrode of the thin film transistor which faces the channel region with a gate insulating film interposed therebetween and extending in the second direction which intersects the first direction in plan view,

the main line portion including an inside-groove portion which is provided inside a groove which is etched in the substrate and covers at least a part of the channel region from the side.

15. The electro-optical device according to claim 1,

the thin film transistor including semiconductor layer having a channel region which extends in the first direction, and

the scanning line including a main line portion having a gate electrode of the thin film transistor which faces the channel region with a gate insulating film interposed therebetween and extending in the second direction which intersects the first direction in plan view,

the main line portion including an inside-groove portion which extends in the second direction and is provided an inside groove which is etched in the substrate, and an outside-groove portion which extends in the second direction and is provided outside the inside groove.

16. The electro-optical device according to claim 1,

a plurality of pixel electrodes are arranged in a plane and include a first pixel electrode group which is inversely driven at a first period and a second pixel electrode group which is inversely driven at a second period which is complementary to the first period,

at least one of the data line or the shielding layer including a main line portion which is extended to an upper side of the scanning line so as to intersect the scanning line, and an overhanging portion which overhangs the scanning line;

a counter electrode which faces the plurality of the pixel electrodes on a counter substrate which is provided opposite to the substrate; and

convex portions being formed on base surfaces of the pixel electrodes on the substrate corresponding to the overhanging portions, the convex portions being regions of gaps between the pixel electrodes, which are adjacent to each other with scanning lines interposed therebetween in plan view.

17. The electro-optical device according to claim 1,

a plurality of pixel electrodes are arranged in a plane and include a first pixel electrode group which is inversely driven at a first period and a second pixel electrode group which is inversely driven at a second period which is complementary to the first period;

a counter electrode which faces the plurality of the pixel electrodes on a counter substrate which is provided opposite to the substrate; and

convex portions formed in regions of gaps between the pixel electrodes which are adjacent to each other in plan view,

the convex portions having gentle step differences which are formed by removing planarization films which are formed in advance on the convex portions by an etching process and causing the surfaces of the convex portions which are exposed after removing to be receded.

19. The electro-optical device according to claim 11, the surrounding portion extending to entirely surround the semiconductor layer from the main line portion.

18. An electronic apparatus including an electro-optical device, the electro-optical device comprising, above a substrate:

a data line extending in a first direction;

a scanning line extending in a second direction which intersects the data line;

a pixel electrode and a thin film transistor provided so as to correspond to an intersection region of the data line and the scanning line;

a storage capacitor electrically connected to the thin film transistor and the pixel electrode,

dielectric films which constitute the storage capacitor being made of at least two layers including different materials and one of the at least two layers being made of a material having a higher dielectric constant than that of the other layer;

a relay layer that electrically connects the pixel electrode and the storage capacitor and that at least partially covers the storage capacitor to shade the storage capacitor from incident light; and

a light shielding layer provided between the data line and the pixel electrode, the light shielding layer being formed along the data line and having a width wider than the width of the data line, the light shielding layer being formed to cover the entire data line in plan view, the light shielding layer at least partially covering the storage capacitor.

20. An electro-optical device comprising, above a substrate:

a data line extending in a first direction;

a scanning line extending in a second direction which intersects the data line;

a pixel electrode and thin film transistor provided so as to correspond to an intersection region of the data line and the scanning line;

a storage capacitor electrically connected to the thin film transistor and the pixel electrode; and

a relay layer that electrically connects the pixel electrode and the storage capacitor and that at least partially covers the storage capacitor to shade the storage capacitor from incident light.