Array substrate for use in a transflective liquid crystal display device and a method of fabricating the same

• US 20010052952A1
• Filed: 06/12/2001
• Published: 12/20/2001
• Est. Priority Date: 06/13/2000
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Philips LCD Company Limited (LG Display Co., Ltd.)
• Inventors: Park, Ki-Bok, Choo, Kyo-Seop
• Granted Patent: US 7,696,529 B2
• Time in Patent Office: Days
• US Class Current: 349/43
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer

Abstract

The present invention provides a transflective liquid crystal display device having at least one switching element having at least a drain electrode, a first passivation layer formed over the switching element with the first passivation layer defining a drain contact hole exposing a first portion the drain electrode, a transparent pixel electrode contacting the drain electrode through the drain contact hole and defining a contact opening that exposes a second portion of the drain electrode, the contact opening being defined in a portion of the transparent pixel electrode in the drain contact hole, and a reflective pixel electrode contacting the transparent pixel electrode in the drain contact hole and contacting the drain electrode through the contact opening.

Claims

1. A transflective liquid crystal display device having a plurality of thin film transistor switching elements on a substrate, each switching element including a gate electrode, a source electrode and a drain electrode, the array substrate comprising:

at least one switching element having at least a drain electrode;

a first passivation layer formed over the switching element, the first passivation layer defining a drain contact hole exposing a first portion the drain electrode;

a transparent pixel electrode contacting the drain electrode through the drain contact hole and defining a contact opening that exposes a second portion of the drain electrode, the contact opening being defined in a portion of the transparent pixel electrode in the drain contact hole; and

a reflective pixel electrode contacting the transparent pixel electrode in the drain contact hole and contacting the drain electrode through the contact opening.

2. The transflective liquid crystal display device according to

claim 1

, wherein the transparent pixel electrode is formed in a pixel region that is defined by pairs of gate lines and data lines.

3. The transflective liquid crystal display device according to

claim 1

, wherein the second portion of the drain electrode is within the first portion of the drain electrode.

4. The transflective liquid crystal display device according to

claim 1

, wherein the reflective electrode includes at least one of aluminum (Al) and an aluminum alloy (Al-alloy).

5. The transflective liquid crystal display device according to

claim 4

, wherein the aluminum alloy includes aluminum niobium (AlNb).

6. The transflective liquid crystal display device according to

claim 1

, wherein the drain contact hole and the contact opening have a quadrilateral shape.

7. The transflective liquid crystal display device according to

claim 6

, wherein the quadrilateral shape is one of rectangular and square.

8. The transflective liquid crystal display device according to

claim 1

, wherein the drain contact hole and the contact openings have a circular shape.

9. The transflective liquid crystal display device according to

claim 1

, wherein the drain contact hole and the contact openings are oval shaped.

10. A transflective liquid crystal display device having a plurality of thin film transistor switching elements on a substrate, each switching element including a gate electrode, a source electrode and a drain electrode, the array substrate comprising:

at least one switching element having at least a drain electrode;

a first passivation layer formed over the switching element, the first passivation layer defining a first drain contact hole exposing a first portion the drain electrode;

a transparent pixel electrode contacting the drain electrode through the first drain contact hole and defining a contact opening that exposes a second portion of the drain electrode, the contact opening being defined in a portion of the transparent pixel electrode in the first drain contact hole;

a second passivation layer covering at least a portion of the transparent pixel electrode, the second passivation layer having a second drain contact hole formed over the first drain contact hole, wherein the second drain contact hole exposes a portion of the transparent pixel electrode in the first drain contact hole and also exposes the second portion of the drain electrode via the contact opening; and

a reflective pixel electrode contacting the transparent pixel electrode in the second drain contact hole and contacting the drain electrode through the contact opening.

11. The transflective liquid crystal display device according to

claim 10

, wherein the transparent pixel electrode is formed in a pixel region that is defined by pairs of gate lines and data lines.

12. The transflective liquid crystal display device according to

claim 10

, wherein the reflective pixel electrode is formed on the second passivation layer.

13. The transflective liquid crystal display device according to

claim 10

, wherein the second portion of the drain electrode is within the first portion of the drain electrode.

14. The transflective liquid crystal display device according to

claim 10

, wherein the reflective electrode includes at least one of aluminum (Al) and an aluminum alloy (Al-alloy).

15. The transflective liquid crystal display device according to

claim 14

, wherein the aluminum alloy includes aluminum niobium (AlNb).

16. The transflective liquid crystal display device according to

claim 10

, wherein the first drain contact hole, the second drain contact hole, and the contact opening have a quadrilateral shape.

17. The transflective liquid crystal display device according to

claim 16

, wherein the quadrilateral shape is one of rectangular and square.

18. The transflective liquid crystal display device according to

claim 10

, wherein the first drain contact hole, the second drain contact hole, and the contact openings have a circular shape.

19. The transflective liquid crystal display device according to

claim 10

, wherein the first drain contact hole, the second drain contact hole, and the contact openings are oval shaped.

20. A method of fabricating a transflective liquid crystal display device, comprising the steps of:

forming a plurality of gate lines and a plurality of gate electrodes on a substrate;

forming a gate insulation layer on the substrate to cover the plurality of gate lines and the plurality of gate electrodes;

forming an active layer on the gate insulation layer;

forming an ohmic contact layer on the active layer;

forming a plurality of data lines on the gate insulation layer, each data line is perpendicular to the plurality of gate lines;

forming source and drain electrodes with the data lines on the active layer and over each gate electrode, the source and drain electrodes being spaced apart from each other;

forming a first passivation layer on the gate insulation layer to cover the data lines and the source and drain electrodes;

forming a first drain contact hole in the first passivation layer to expose a first portion of the drain electrode;

forming a transparent pixel electrode on the first passivation layer;

forming a contact opening in the first drain contact hole, the transparent pixel electrode contacting the first portion of the drain electrode through the first drain contact hole;

forming a second passivation layer on the first passivation layer to cover the transparent pixel electrode;

forming a second drain contact hole in the second passivation layer over the first drain contact hole;

forming a reflective conductive material on the second passivation layer having the second drain contact hole;

forming a reflective pixel electrode from the reflective conductive material; and

forming a transmitting hole, wherein the reflective pixel electrode contacts the transparent pixel electrode through the second drain contact hole and contacts the drain electrode through the contact opening.

21. The method according to

claim 20

, wherein the first passivation layer includes at least one of benzocyclobutene (BCB) and an acryl-based resin.

22. The method according to

claim 20

, wherein the reflective conductive material includes at least one of aluminum (Al) and an aluminum alloy (Al-alloy).

23. The method according to

claim 22

, wherein the aluminum alloy includes aluminum niobium (AlNb).

24. The method according to

claim 20

, wherein the first drain contact hole, the second drain contact hole, and the contact opening have a quadrilateral shape.

25. The method according to

claim 24

, wherein the quadrilateral shape is one of a rectangle and a square.

26. The method according to

claim 20

, wherein the first drain contact hole, the second drain contact hole, and the contact opening are shaped like a circle.

27. The method according to

claim 20

, wherein the first drain contact hole, the second drain contact hole and the contact opening are shaped like an oval.