Liquid crystal display device and method of fabricating same

• US 20050270452A1
• Filed: 06/02/2005
• Published: 12/08/2005
• Est. Priority Date: 06/05/2004
• Status: Active Grant

• Current Assignee: LG Philips LCD Company Limited (LG Display Co., Ltd.)
• Original Assignee: LG Philips LCD Company Limited (LG Display Co., Ltd.)
• Inventors: Lee, Ji No, Ahn, Byung Chul, Kwack, Hee Young, Jung, Tae Yong
• Granted Patent: US 7,583,337 B2
• Time in Patent Office: Days
• US Class Current: 349/114
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/1362 Active matrix addressed cells G02F1/134336, G02F1/134363 take precedence
• CPC Class Codes: G02F 1/136231 for reducing the number of lithographic steps

Abstract

A liquid crystal display device is provided that comprises a gate line; a first insulating film on the gate line; a data line crossing the gate line to define a pixel region, the pixel region having a transmissive area and a reflective area; a thin film transistor connected to the gate line and the data line; a pixel electrode formed in the pixel region ; a second insulating film on the thin film transistor; a storage capacitor including a storage upper electrode overlapping the gate line; a transmission hole exposing at least a portion of the pixel electrode, and a reflective electrode formed in the reflective area of the pixel region, the reflective electrode connecting the pixel electrode with thin film transistor and the storage upper electrode, wherein the gate line and the pixel electrode include a first transparent conductive layer.

Claims

1. A liquid crystal display device, comprising:

a gate line including a first transparent conductive layer;

a first insulating film on the gate line;

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

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

a pixel electrode having a first transparent conductive layer;

a storage capacitor including a storage upper electrode overlapping the gate line;

a transmission hole exposing at least a portion of the first transparent conductive layer of the pixel electrode; and

a reflective electrode formed in the reflective area of the pixel region, the reflective electrode connecting the pixel electrode with thin film transistor and the storage upper electrode.

2. The device according to claim 1, further comprising a second conductive layer on the first transparent conductive layer of the gate line.

3. The device according to claim 1, further comprising a second conductive layer on the boundary of the first transparent conductive layer of the pixel electrode.

4. The device according to claim 2, further comprising:

a double layered gate pad extending from the gate line, wherein a portion of a first conductive layer of the double layered gate pad is exposed via a first contact hole by passing through the first insulating film and a second conductive layer of the double layered gate pad.

5. The device according to claim 4, further comprising:

a double layered data pad connected to the data line, wherein a portion of a first conductive layer of the double layered data pad is exposed via a second contact hole by passing through the gate insulating film and a second conductive layer of the double layered data pad.

6. The device according to claim 5, further comprising a second insulating film on the thin film transistor.

7. The device according to claim 6, wherein the second insulating film is removed in the gate and data pads.

8. The device according to claim 6, further comprising a third insulating film between the thin film transistor and the second insulating film.

9. The device according to claim 8, wherein the third insulating film is an inorganic insulating material.

10. The device according to claim 6, further comprising a third insulating film between the second insulating film and the reflective electrode.

11. The device according to claim 10, wherein the third insulating film is an inorganic insulating material.

12. The device according to claim 3, wherein the reflective electrode is directly connected to the first transparent conductive layer of the pixel electrode and substantially laterally connected to the second conductive layer of the pixel electrode through the transmission hole.

13. The device according to claim 5, further comprising:

a double layered data link extending from the data pad; and

a first contact electrode of the same metal as the reflective electrode connecting the data line and the data line through third and fourth contact holes exposing the data line and the data link.

14. The device according to claim 13, further comprising an electrostatic discharging device connected to one of the data and gate lines.

15. The device according to claim 14, 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 the 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 fifth contact hole and a sixth contact hole exposing the source and gate electrodes;

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

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

16. The device according to claim 15, wherein the second, third and fourth contact electrodes are formed of the same metal as the reflective electrode.

17. The device according to claim 15, wherein the gate electrodes have a double layered structure.

18. The device according to claim 17, wherein the fourth, sixth, eighth, tenth contact holes expose a first conductive layer of the double layered structure electrodes by passing through a second conductive layer of the gate electrodes.

19. The device according to claim 15, wherein the first to fourth contact electrodes are formed inner portion from a sealant region.

20. The device according to claim 15, wherein the reflective electrode and the first to fourth contact electrodes are formed of AlNd and Mo.

21. The device according to claim 6, wherein the insulating film has an embossed surface.

22. The device according to claim 21, wherein the reflective electrode has an embossed surface in a reflective area.

23. The device according to claim 6, wherein the second insulating film is an organic material.

24. The device according to claim 1, wherein the storage upper electrode substantially overlaps more than half of the gate line in the direction of the data line.

25. The device according to claim 1, wherein the reflective electrode connects the pixel electrode with the thin film transistor and the storage upper electrode through the transmission hole.

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

forming a gate pattern including a first transparent conductive layer using a first mask, the gate pattern including a pixel electrode, a gate electrode and a gate line;

forming a first insulating film on the gate pattern;

forming a semiconductor layer and a source/drain pattern on the first insulating film using a second mask, the source/drain pattern having a storage upper electrode, a drain electrode, a source electrode, and a data line;

forming a second insulating film over the source/drain pattern using a third mask;

forming a transmission hole exposing the first transparent conductive layer of the pixel electrode using a fourth mask; and

forming a reflective electrode in a reflective area using a fifth mask, the reflective electrode connecting the pixel electrode with the drain electrode and the storage upper electrode through the transmission hole.

27. The method according to claim 26, wherein the semiconductor layer overlaps with the data line.

28. The method according to claim 26, wherein the transmission hole passes through the first insulating film and a second conductive layer of the pixel electrode.

29. The method according to claim 26, wherein the transmission hole overlaps with an aperture portion of the second insulating film.

30. The method according to claim 28, further comprising a third insulating film on at least one of the source/drain pattern and the second insulating film.

31. The method according to claim 30, wherein the transmission hole passes through the third insulating film.

32. The method according to claim 26, wherein the gate pattern is formed of a double layer having a first conductive layer and a second conductive layer.

33. The method according to claim 32, further comprising:

forming a double layered gate pad using the first mask, the gate pad being connected to the gate line;

forming a double layered data pad using the first mask, the data pad being connected to the data line;

removing the second insulating film in a pad region of the gate and data pads using the third mask; and

forming first and second contact holes exposing a first conductive layer of gate and data pads using the fourth mask.

34. The method according to claim 33, further comprising:

forming a double layered data link extending from the data pad using the first mask;

forming second and third aperture portions using the third mask;

forming third and fourth contact holes exposing the data line and the data link using the fourth mask; and

forming a first contact electrode to connect the data line and the data link through the third and fourth contact holes using the fifth mask.

35. The method according to claim 34, wherein second and third aperture portions overlap with the data line and the data link.

36. The method according to claim 34, further comprising:

forming an electrostatic discharging device having a second thin film transistor connected to one of the data and gate 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 the gate electrode and the drain electrode of the second thin film transistor in a diode form.

37. The method according to claim 36, wherein the forming the electrostatic discharging device includes:

forming the gate electrodes of the second to fourth thin film transistors using the first mask;

forming the semiconductor layers, the source electrodes and the drain electrodes of the second to fourth transistors on the first insulating film using the second mask;

forming fourth to ninth aperture portions on the second insulating film using the third mask;

forming fifth to tenth contact holes exposing electrodes overlapping with the fourth to ninth aperture portions using the fourth mask; and

forming second to fourth contact electrodes using the fifth mask.

38. The method according to claim 37, wherein the fourth and fifth aperture portions overlap a source electrode and a gate electrode of the third thin film transistor.

39. The method according to claim 37, wherein the sixth and seventh aperture portions overlap a drain electrode of the third or fourth thin film transistors and a gate electrode of the second thin film transistor.

40. The method according to claim 37, wherein the eighth and ninth aperture portions overlap a source electrode and a gate electrode of the fourth thin film transistor.

41. The method according to claim 37, wherein the second contact electrode connects to a source electrode and a gate electrode of the third thin film transistor through the fifth and sixth contact holes.

42. The method according to claim 37, wherein the third contact electrode connects to a drain electrode of the third or fourth thin film transistor and the gate electrode of the second thin film transistor through the seventh and eighth contact holes.

43. The method according to claim 37, wherein the fourth contact electrode connects to a source electrode and a gate electrode of the fourth thin film transistor through the ninth and tenth contact holes.

44. The method according to claim 37, wherein the first to fourth contact electrodes are formed inner portion from a sealant area.

45. The method according to claim 37, wherein the reflection electrode and the first to fourth contact electrodes are formed of AlNd and Mo.

46. The method according to claim 26, wherein the second insulating film is an organic material.

47. The method according to claim 26, wherein the second insulating film has an embossed surface.

48. The method according to claim 26, wherein the reflection electrode has an embossed surface.

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

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

forming a first insulating film and a semiconductor layer on the gate pattern, and a source/drain pattern having a storage upper electrode, a drain electrode, a source electrode, a data line using a second mask;

forming a transmission hole exposing the first conductive layer of the pixel electrode in a transmissive area using a third mask;

forming a second insulating film over the source/drain pattern using a fourth mask; and

forming a reflective electrode in a reflective area using a fifth mask, the reflective electrode connecting the pixel electrode with the drain electrode and the storage electrode through the transmission hole.

50. The method according to claim 49, wherein the semiconductor layer overlaps with the data line.

51. The method according to claim 49, wherein forming the transmission hole further comprises:

forming a third insulating film that covers the source/drain pattern.

52. The method according to claim 51, wherein the transmission hole penetrates from the third insulating film to the second conductive layer of the pixel electrode.

53. The method according to claim 49, further comprising:

forming a double layered gate pad using the first mask, the gate pad being connected to the gate line;

forming a double layered data pad using the first mask, the data pad being connected to the data line;

forming first and second contact holes exposing a first conductive layer of gate and data pads using the third mask; and

removing the second insulating film in a pad area of the gate and the data pads using the fourth mask.

54. The method according to claim 49, further comprising:

forming a double layered data link using the first mask, the data link extending from the data pad;

forming third and fourth contact holes exposing the data line and the data link using the third mask;

extending the third and fourth contact holes to the insulating film using the fourth mask; and

forming a first contact electrode to connect the data line and the data link through the third and fourth contact holes using the fifth mask.

55. The method according to claim 49, further comprising:

forming a electrostatic discharging device having a second thin film transistor connected to one of the data and gate 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.

56. The method according to claim 55, wherein forming the electrostatic discharging device comprises:

forming the gate electrodes of the second to fourth thin film transistors using the first mask;

forming the semiconductor layers, the source electrodes, and the drain electrodes of the second to fourth transistors on the gate insulating film using the second mask;

forming fifth to tenth contact holes using the third mask;

extending the fifth to tenth contact holes to the second insulating film using the fourth mask; and

forming second to fourth contact electrodes that using the fifth mask.

57. The method according to claim 56, wherein the fifth and sixth contact holes expose the gate and source electrodes of the third thin film transistor.

58. The method according to claim 56, wherein the seventh and eighth contact holes expose the drain electrode of the third or fourth thin film transistor and the gate electrode of the second thin film transistor.

59. The method according to claim 56, wherein the ninth and tenth contact holes expose the source and drain electrodes of the fourth thin film transistor.

60. The method according to claim 56, wherein the second contact electrode connects to the gate and source electrodes of the third thin film transistor through the fifth and sixth contact holes.

61. The method according to claim 56, wherein the third contact electrode connects the drain electrode of the third or fourth thin film transistor and the gate electrode of the second thin film transistor through the seventh and eighth contact holes.

62. The method according to claim 56, wherein the fourth contact electrode connects the gate and source electrodes of the fourth thin film transistor through the ninth and tenth contact holes.

63. The method according to claim 56, wherein the first to fourth contact electrodes are formed in a sealant area.

64. The method according to claim 56, wherein the reflection electrode and the first to fourth contact electrodes are formed of AlNd and Mo.

65. The method according to claim 49, wherein the second insulating film is an organic material.

66. The method according to claim 49, wherein the second insulating film has an embossed surface.

67. The method according to claim 49, wherein the reflection electrode has an embossed surface.

68. A liquid crystal display device, comprising:

a gate line;

a gate insulating film on the gate line;

a data line crossing the gate line to define a pixel region;

a switching element;

a pixel electrode;

a storage capacitor including a storage upper electrode overlapping more than half of the gate line in the direction of the data line; and

a reflective electrode connecting the pixel electrode with the switching element.

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

forming a gate line including a first transparent conductive layer;

forming a gate insulating film on the gate line;

forming a data line crossing the gate line to define a pixel region;

forming a thin film transistor connected to the gate line and the data line;

forming a pixel electrode having a second transparent conductive layer;

forming a storage capacitor including a storage upper electrode overlapping the gate line;

forming a transmission hole exposing at least a portion of the second transparent conductive layer of the pixel electrode; and

forming a reflective electrode connecting the pixel electrode with the thin film transistor and the storage upper electrode.