Electrooptical device, projection-type display apparatus, and method for manufacturing the electrooptical device

• US 20030210363A1
• Filed: 05/05/2003
• Published: 11/13/2003
• Est. Priority Date: 04/21/2000
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Yasukawa, Masahiro, Yamazaki, Yasushi
• Granted Patent: US 6,768,522 B2
• Time in Patent Office: Days
• US Class Current: 349/110
• CPC Class Codes: G02F 1/133553 Reflecting elements associated to illuminating devices G02F1/133605
• 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 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: H01L 29/78633 with a light shield

Abstract

In a TFT array substrate 10 of an electrooptical device, a scanning line 3a, a drain electrode 11, a first light shield layer 13, and a data line 3a are laminated over a channel region 1a′ of a TFT 30 and a second light shield layer 14 is laminated beneath the channel region 1a′. A side wall formation trench 16 is formed beside the channel region 1a′ of the TFT 30, and in the side wall formation trench a conductive layer having a light shield property is concurrently formed with the first light shield layer 13 thereby a light shield side wall 131 is formed. By three-dimensionally blocking light'"'"'s entry towards the channel region 1a′, obliquely or laterally incident light is prevented from entering the channel region of a pixel switching TFT, and the TFT 30 is free from erratic operations and reliability degradation.

Claims

1. An electrooptical device comprising, above a substrate:

a pixel electrode;

a thin-film transistor coupled to the pixel electrode;

a wiring connected to the thin-film transistor; and

a light shield member three-dimensionally covering the thin-film transistor and the wiring.

2. The electrooptical device according to claim 1, wherein the light shield member further comprises one light shield layer deposited on the bottom surface and the side portion of a trench formed in the substrate and accommodating the thin-film transistor and the wiring, and

another light shield layer covering the trench from above.

3. The electrooptical device according to claim 1, wherein the light shield member further comprises a lower light shield layer deposited on the substrate,

an upper light shield layer deposited above the thin-film transistor and the wiring, formed above the lower light shield layer, and

a side portion light shield layer filling a groove formed from the upper light shield layer to the lower light shield layer outside the thin-film transistor and the wiring in a plan view.

4. The electrooptical device according to claim 1, wherein the light shield member further comprises:

in one plane area thereof, one light shield layer deposited on a bottom surface and a side portion of a trench formed in the substrate and accommodating the thin-film transistor and the wiring, and another light shield layer covering the trench from above; and

in another plane area, a lower light shield layer deposited above the substrate, an upper light shield layer deposited above the thin-film transistor and the wiring, formed on the lower light shield layer, and a side wall light shield layer filling a groove formed from the upper light shield layer to the lower light shield layer outside the thin-film transistor and the wiring in a plan view.

5. The electrooptical device according to claim 1, wherein the light shield member further comprises:

one light shield layer deposited on the bottom surface and the side portion of a trench formed in the substrate and partly accommodating the thin-film transistor and the wiring;

an upper light shield layer deposited above the thin-film transistor and the wiring formed above the one light shield layer; and

a side portion light shield layer filling a groove formed from the upper light shield layer to the one light shield layer outside the thin-film transistor and the wiring in a plan view.

6. The electrooptical device according to claim 5, wherein the upper light shield layer and the side portion light shield layer are integrally formed.

11. The electrooptical device according to claim 1, wherein the pixel electrode and the thin-film transistor are coupled to each other through an electrically conductive layer having a light shield property.

12. The electrooptical device according to claim 1, wherein a junction point between the pixel electrode and the thin-film transistor is positioned at the center between adjacent thin-film transistors in a plan view.

13. The electrooptical device according to claim 1, comprising a light shield layer facing the substrate and facing a junction point between the pixel electrode and the thin-film transistor.

14. The electrooptical device according to claim 1, wherein the light shield member is formed of a film containing a refractory metal.

15. The electrooptical device according to claim 1, wherein the wiring further includes scanning lines and data lines intersecting each other, and the light shield member is configured in a grid in a plan view.

16. The electrooptical device according to claim 1, further comprising a storage capacitor formed in a space three-dimensionally covered with the light shield member on the first substrate, and connected to the pixel electrode.

7. An electrooptical device having a pair of first and second substrates with an electrooptical material disposed therebetween, and including above the first substrate:

a plurality of pixel electrodes arranged two-dimensionally, including a first pixel electrode group which is driven by an alternating driving method with a first period, and a second pixel electrode group which is driven in an alternating driving method with a second period that is complimentary to the first period;

a thin-film transistor connected to each pixel electrode;

a wiring connected to each thin-film transistor;

a light shield member which three-dimensionally covers the thin-film transistor and the wiring in a gap area between adjacent pixel electrodes in a plan view and protrudes in a ridge a portion of the gap area between adjacent pixel electrodes of different pixel electrode groups;

and including above the second substrate, a counter electrode facing the plurality of pixel electrodes.

8. The electrooptical device according to claim 7, wherein the light shield member comprises:

in an area between adjacent pixel electrodes of the same group, one light shield layer deposited on a bottom surface and a side wall of a trench formed in the substrate and accommodating the thin-film transistor and the wiring, and another light shield layer covering the trench from above;

and in an area between adjacent pixel electrodes of the different pixel electrode groups, a lower light shield layer deposited above the substrate, an upper light shield layer deposited above the thin-film transistor and the wiring, formed on the lower light shield layer, and a side portion light shield layer filling a groove formed from the upper light shield layer to the lower light shield layer outside the thin-film transistor and the wiring in a plan view.

9. The electrooptical device according to claim 8, wherein a planarizing process is performed on an underlayer under the pixel electrode in the area between the adjacent pixel electrodes of the same pixel electrode group.

10. The electrooptical device according to claim 8, wherein the upper light shield layer and the side portion light shield layer are integrally formed.

17. A projection-type display apparatus, comprising:

a light valve including, above a substrate, a pixel electrode, a thin-film transistor connected to the pixel electrode, a wiring connected to the thin-film transistor, and a light shield member three-dimensionally covering the thin-film transistor and the wiring;

a light source for directing light to the light valve; and

an optical system for projecting a light beam from the light valve.