Liquid crystal display device and fabricating method having reflective electrode connecting pixel electrode with drain and upper storage capacitor electrodes at edge of transmission hole

• US 7,528,909 B2
• Filed: 05/31/2005
• Issued: 05/05/2009
• 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
• Primary Examiner(s): Nelms; David
• Assistant Examiner(s): HEYMAN, JOHN S
• Application Number:
  US11/139,501
• Publication Number:
  US 20050270450A1
• Time in Patent Office: 1,435 Days
• Field of Search: 349/114, 349/46, 349/113, 349/147
• US Class Current: 349/114
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/13458 Terminal pads
• CPC Class Codes: G02F 1/136231 for reducing the number of lithographic steps
• CPC Class Codes: G02F 1/136236 using a grey or half tone lithographic process
• CPC Class Codes: G02F 1/13624 having more than one switching element per pixel
• CPC Class Codes: G02F 1/13629 Multilayer wirings

Abstract

A method of fabricating a LCD device includes forming a gate line, a gate electrode, and a pixel electrode having a double-layer structure on a first substrate using a first mask, the double-layer structure including first and second conductive layers; forming a first insulation film, a semiconductor pattern on the first insulation film, a source/drain pattern having an upper storage electrode, source and drain electrodes, a data line using a second mask, the data and gate lines defining a pixel region having transmission and reflection areas; forming a second insulation film on the source/drain pattern and a transmission hole by passing through the second insulation film to the second conductive layer in the transmission area using a third mask; and forming a reflective electrode in the reflection area using a fourth mask, the reflective electrode connecting the pixel electrode with the drain electrode and the storage electrode.

Claims

1. A liquid crystal display device, comprising:

a first substrate and a second substrate;

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 film on the gate line;

a data line crossing the gate line to define a pixel region, the pixel region having a transmission area and a reflection area;

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

a pixel electrode having the first transparent conductive layer and the second opaque conductive layer along a boundary of the first transparent conductive layer;

a upper storage electrode over the gate line with the gate insulating film therebetween for forming a storage capacitor;

a transmission hole passing through the second opaque conductive layer of the pixel electrode from a second insulation film to expose the first transparent conductive layer of the pixel electrode;

a reflective electrode in the reflection area, the reflective electrode connecting the pixel electrode with a drain electrode and the upper storage electrode at an edge of the transmission hole;

a gate pad extended from the gate line, the gate pad including the first transparent conductive layer exposed through a first pad contact hole, the first pad contact hole passing through the second insulation film to the second opaque conductive layer;

a data pad connected to the data line via a data link, the data pad including the first transparent conductive layer exposed through a second pad contact hole, the second pad contact hole passing through the second insulation film to the second opaque conductive layer; and

a liquid crystal layer between the first and second substrates.

2. The device of claim 1, wherein the second insulation film is formed of an organic material.

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

4. The device of claim 3, wherein the transmission hole passes through the third insulation film.

5. The device of claim 1, further comprising:

a first contact hole passing through the second insulation film, the data line, the first insulation film and the second opaque conductive layer of the data link to expose the first transparent conductive layer, the data link having the double-layer structure and overlapping an end of the data line; and

a first contact electrode laterally connected to the data line and the second opaque conductive layer via the first contact hole, and connected to a surface of the data link.

6. The device of claim 5, wherein the first contact electrode is formed of the same metal as the reflective electrode.

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

8. The device of claim 7, wherein the electrostatic discharging device includes:

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

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 the second contact hole;

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

9. The device of claim 8, wherein the gate electrodes of the second, third, and fourth thin film transistors are formed of the double-layer structure.

10. The device of claim 8, wherein the second, third, and fourth contact electrodes are formed of the same material as the reflective electrode.

11. The device of claim 8, wherein the second, third, and fourth contact holes penetrate the second insulation film, the source or drain electrode, the semiconductor pattern, the first insulation film and the second conductive layer of the gate electrode to expose the fist conductive layer of the gate electrode.

12. The device of claim 8, wherein the first, second, third and fourth contact electrodes are formed between a sealant and an active area on which an image is displayed.

13. The device of claim 1, wherein the second insulation film has an embossed surface.

14. The device of claim 13, wherein the reflective electrode has the embossed surface.

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

providing a first substrate and a second substrate;

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

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

forming a second insulation film on the source/drain pattern and a transmission hole by passing through the second insulation film to the second opaque conductive layer of the pixel electrode in the transmission area to expose the first transparent conductive layer of the pixel electrode using a third mask; and

forming a reflective electrode in the reflection area using a fourth mask, the reflective electrode connecting the pixel electrode with the drain electrode and the storage electrode at an edge of the transmission hole.

16. The method of claim 15, wherein the data line overlaps the semiconductor pattern.

17. The method of claim 15,wherein the second insulation film is formed of an organic material.

18. The method of claim 15, wherein the forming the transmission hole further includes forming a third insulation film on the source/drain pattern.

19. The method of claim 18, wherein the transmission hole is formed by passing through the third insulation film.

20. The method of claim 15, further comprising:

forming a gate pad extended from the gate line and a data pad connected to the data line using the first mask; and

forming first and second pad contact holes by passing through the second insulation film in the gate and data pad regions to the second opaque conductive layer of the gate and data pads using the third mask.

21. The method of claim 20, wherein the gate and data pads have the double-layer structure.

22. The method of claim 20, wherein the forming the transmission hole, the first pad contact hole and the second pad contact hole includes:

forming and patterning the second insulation film using the third mask to form the transmission hole, the first and the second pad contact holes in the second insulation film;

forming an embossed surface of the second insulation film in the reflection region by curing the patterned second insulation film; and

penetrating the transmission hole, the first pad contact hole and the second pad contact hole to the pixel electrode and the second conductive layer of the gate pad and the data pad using the cured second insulation film as a mask.

23. The method of claim 22, wherein the third mask includes one of a half-tone mask and diffractive exposure mask.

24. The method of claim 15, further comprising:

forming a data link extended from the data pad to overlap with an end of the data line using the first mask;

forming a first contact hole by exposing the first transparent conductive layer of the data link by penetrating from the second insulation film through the data line to the second opaque conductive layer of the data link using the third mask; and

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

25. The method of claim 24, wherein the first contact electrode is formed between a sealant and an active area on which an image is displayed.

26. The method of claim 15, further comprising forming an electrostatic discharging device,

wherein the electrostatic discharging device includes:

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

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.

27. The method of claim 26, wherein the forming the electrostatic discharging device includes:

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

forming semiconductor patterns and source and drain electrodes of the second, third, and fourth thin film transistors on the first insulation film 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.

28. The method of claim 27, wherein the second contact hole is formed at an overlap portion of the source electrode and the gate electrode of the third thin film transistor, the third contact hole is formed at an overlap portion of the drain electrode of the third or the fourth thin film transistor and the gate electrode of the second thin film transistor and the fourth contact hoe is formed at an overlap portion of the source electrode and the gate electrode of the fourth thin film transistor.

29. The method of claim 27, wherein the second contact electrode connected to the source electrode and the gate electrode of the third thin film transistor through the second contact hole, the third contact electrode connected 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, and the fourth contact electrode exposing the source electrode and the gate electrode of the fourth thin film transistor through the fourth contact hole.

30. The method of claim 27, wherein the second, third and fourth contact electrodes are formed between a sealant and an active area on which an image is displayed.