Liquid crystal display device and fabricating method thereof

• US 20050270454A1
• Filed: 06/03/2005
• Published: 12/08/2005
• Est. Priority Date: 06/05/2004
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Ahn, Byung Chul, Park, Jong Woo
• Granted Patent: US 7,760,309 B2
• Time in Patent Office: Days
• US Class Current: 349/114
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/13458 Terminal pads
• CPC Class Codes: G02F 1/1362 Active matrix addressed cells G02F1/134336, G02F1/134363 take precedence

Abstract

A liquid crystal display device is provided that includes: first and second substrate; a gate line of a double layer having a first transparent conductive layer and a second opaque conductive layer on the first substrate; a first insulation layer on the gate line; a data line crossing the gate line to define a pixel region, the pixel region having a transmissive region and a reflective region; a thin film transistor connected to the gate and data lines; a pixel electrode formed of the transparent conductive layer in the pixel region; an upper storage electrode forming a storage capacitor by overlapping the gate line with the first insulation layer there between; a transmission hole to exposing the pixel electrode by passing through a second insulation layer on the thin film transistor to the first insulation layer; a reflective electrode connecting the pixel electrode with a drain electrode and the upper storage electrode through an edge part of the transmission hole; a gate pad extending from the first conductive layer of the gate line; a data pad formed of the first conductive layer and connected to the data line through a data link; and a liquid crystal layer between the first and second substrates, wherein the first and second insulation layers are removed in the gate and data pads.

Claims

1. A liquid crystal display device, comprising:

first and second substrates;

a gate line having a double layer structure including a first transparent conductive layer and a second opaque conductive layer on the first substrate;

a first insulation layer on the gate line;

a data line crossing the gate line to define a pixel region, the pixel region having a transmissive region and a reflective region;

a thin film transistor connected to the gate and data lines;

a pixel electrode formed of the transparent conductive layer in the pixel region;

an upper storage electrode to form a storage capacitor by overlapping the gate line with the first insulation layer there between;

a transmission hole exposing the pixel electrode by passing through a second insulation layer on the thin film transistor to the first insulation layer;

a reflective electrode connected to the pixel electrode with a drain electrode and the upper storage electrode exposed through an edge part of the transmission hole;

a gate pad extending from the first conductive layer of the gate line;

a data pad formed of the first conductive layer and connected to the data line through a data link; and

a liquid crystal layer between the first and second substrates;

wherein the first and second insulation layers are removed in the gate and data pads.

2. The device of claim 1, further comprising a third insulation layer between the thin film transistor and the second insulation layer

3. The device of claim 2, wherein the third insulation layer is an inorganic material.

4. The device of claim 2, wherein the transmission hole passes through the third insulation layer.

5. The device of claim 1, wherein the second insulation layer is an organic material.

6. The device of claim 1, further comprising:

a first contact hole passing through the second insulation layer, the data line and the first insulation layer exposing the data link, the data link being overlapped with an end part of the data line; and

a first contact electrode substantially laterally connected to the data line via the first contact hole and connected to a surface of the data link.

7. The device of claim 6, wherein the first contact electrode is formed of the same material as the reflective electrode.

8. The device of claim 6, wherein the first contact electrode is formed inner side from a sealant region.

9. The device of claim 6, wherein the reflective electrode and the first contact electrode having a double layer structure of AlNd and Mo.

10. The device of claim 1, further comprising an electrostatic discharging device connected to one of the gate and data lines.

11. The device of claim 10, wherein the electrostatic discharging device comprises:

a second thin film transistor connected to one of the gate and data lines;

a third thin film transistor connected between a gate electrode and a source electrode of the second thin film transistor in a diode form;

a fourth thin film transistor connected between a gate electrode and a drain electrode of the second thin film transistor in a diode form;

a second contact electrode connected to a source electrode and a gate electrode of the third thin film transistor through a second contact hole;

a third contact electrode connected to a drain electrode of the third or fourth thin film transistor to the gate electrode of the second thin film transistor through a third contact hole; and

a fourth contact electrode connected to a source electrode and a gate electrode of the fourth thin film transistor through a fourth contact hole.

12. The device of claim 11, wherein the gate electrodes of the second, third and fourth thin film transistors have a double layer structure.

13. The device of claim 11, wherein the second, third and fourth contact electrodes are formed of the same material as the reflective electrode.

14. The device of claim 11, wherein the second, third and fourth contact holes pass through the source or drain electrode, the semiconductor pattern, the first insulating layer and the second conductive layers of the gate electrodes from the second insulation layer to expose the first conductive layers of the gate electrodes.

15. The device of claim 11, wherein the second, third and fourth contact electrodes are formed inner side from a sealant region.

16. The device of claim 11, wherein the reflective electrode and the second, third and fourth contact electrodes have a double layer structure of AlNd and Mo.

17. The device of claim 1, wherein the second insulation layer has an embossed surface.

18. The device of claim 17, wherein the reflective electrode has an embossed surface.

19. A method of fabricating a liquid crystal display device, comprising:

providing first and second substrates;

forming a gate line and a gate electrode having a double layer structure including a first transparent conductive layer and a second opaque conductive layer, and a pixel electrode having the first conductive layer using a first mask;

forming a first insulation layer on the electrodes;

forming a semiconductor pattern on the first insulation layer, a source/drain pattern having an upper storage electrode, a drain electrode, a source electrode, and a data line using a second mask, the gate and data lines defining a pixel region having a transmissive region and a reflective region;

forming a second insulation layer on the source/drain pattern and a transmission hole penetrating from the second insulation layer to the first insulation layer in the transmissive region using a third mask;

forming a reflective electrode in the reflective region using a fourth mask, the reflective electrode connecting the pixel electrode with the drain electrode and the storage electrode through the transmission hole; and

forming a liquid crystal layer between the first and second substrates.

20. The method of claim 19, wherein the data line overlaps a portion of the semiconductor pattern.

21. The method of claim 20, wherein the reflective region overlaps a portion of the pixel electrode.

22. The method of claim 19, wherein forming the transmission hole comprises:

forming a third insulation layer on the source/drain pattern.

23. The method of claim 22, wherein the third insulation layer is an inorganic material.

24. The method of claim 22, wherein the transmission hole passes through the third insulation layer.

25. The method of claim 19, wherein the second insulation layer is an organic material.

26. The method of claim 19, further comprising:

forming a gate pad extending from the first conductive layer of the gate line and a data pad to be connected to the data line using the first mask; and

removing the first and second insulation layer in a pad region having the gate pad and the data pad using the third mask.

27. The method of claim 26, wherein the gate and data pads have substantially the same structure.

28. The method of claim 26, further comprising:

forming a data link extending from the data pad and overlapping with an end part of the data line using the first mask;

forming a first contact hole penetrating from the second insulation layer via the data line to the first insulation layer to expose the data link using the third mask; and

forming a first contact electrode connected to the exposed data line and the data link through the first contact hole using the fourth mask.

29. The method of claim 28, wherein the first contact electrode is formed inner side from a sealant region.

30. The method of claim 28, wherein the reflective electrode and the first contact electrodes have a double layer structure of AlNd and Mo.

31. The method of claim 19, further comprising forming an electrostatic discharging device comprising:

a second thin film transistor connected to one of the gate and data lines;

a third thin film transistor connected between a gate electrode and a source electrode of the second thin film transistor in a diode form; and

a fourth thin film transistor connected between a gate electrode and a drain electrode of the second thin film transistor in a diode form.

32. The method of claim 31, wherein forming the electrostatic discharging device comprises:

forming the gate electrodes of the second, third and fourth thin film transistors using the first mask, the gate electrodes having the double layer;

forming the drain electrodes, the source electrodes and the semiconductor patterns of the second, third and fourth transistors on the first insulation layer using the second mask;

forming second, third and fourth contact holes using the third mask; and

forming second, third and fourth contact electrodes using the fourth mask.

33. The method of claim 32, wherein the second contact hole is formed in an overlap part of the source electrode and the gate electrode of the third thin film transistor.

34. The method of claim 32, wherein the third contact hole is formed in an overlap part of the drain electrode of the third or the fourth thin film transistor and the gate electrode of the second thin film transistor.

35. The method of claim 32, wherein the fourth contact hole is formed in an overlap part of the source electrode and the gate electrode of the fourth thin film transistor.

36. The method of claim 32, wherein the second contact electrode is connected to the source electrode and the gate electrode of the third thin film transistor through the second contact hole.

37. The method of claim 32, wherein the third contact electrode connects the drain electrode of the third or the fourth thin film transistor to the gate electrode of the second thin film transistor through the third contact hole.

38. The method of claim 32, wherein the fourth contact hole exposes the source electrode and the gate electrode of the fourth thin film transistor through the fourth contact hole.

39. The method of claim 32, wherein the second, third and fourth contact electrodes are formed inner side from a sealant region.

40. The method of claim 32, wherein the reflective electrode and the second, third and fourth contact electrodes have a double layer structure of AlNd and Mo.

41. The method of claim 19, wherein the second insulation layer has an embossed surface.

42. The method of claim 41, wherein the reflective electrode has an embossed surface corresponding to the second insulation layer.