Liquid crystal display and fabricating method thereof

• US 20020180897A1
• Filed: 12/28/2001
• Published: 12/05/2002
• Est. Priority Date: 06/05/2001
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Chae, Gee Sung
• Granted Patent: US 7,342,616 B2
• Time in Patent Office: Days
• US Class Current: 349/39
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G02F 2201/40 Arrangements for improving the aperture ratio

Abstract

A liquid crystal display increases the capacitance of a storage capacitor while increasing aperture ratio. The liquid crystal display includes a gate insulating film entirely covering a gate electrode, and an active layer on the gate insulating film overlaps the gate electrode. An ohmic contact layer is formed on the active layer, and source electrode and drain electrodes are on the ohmic contact layer such that a channel forms between them. A protective layer covers the source and the drain electrodes, and a data line crosses the gate line and connects to the source electrode by piercing the protective layer. A storage electrode is at a pixel cell area of the same layer as the gate electrode and the gate line, and a pixel electrode opposes the storage electrode having the gate insulating film in between them.

Claims

1. A liquid crystal display, comprising:

a gate electrode over a substrate;

a gate insulating film entirely deposited over the substrate to cover said gate electrode;

an active layer formed on said gate insulating film which overlaps with said gate electrode;

an ohmic contact layer formed on said active layer;

a source electrode formed on said ohmic contact layer;

a drain electrode formed on said ohmic contact layer, the drain electrode being opposed to said source electrode to form a channel;

a protective layer covering said source and said drain electrodes;

a storage electrode formed at a pixel cell area of a same layer as said gate electrode; and

a pixel electrode formed to oppose to said storage electrode having said gate insulating film in between said pixel electrode and said storage electrode, and said pixel electrode being electrically connected with said drain electrode.

2. The liquid crystal display according to claim 1, wherein a contact hole connects said source electrode with said data line.

3. The liquid crystal display according to claim 1, further comprising a buffer metal layer on said source and said drain electrodes.

4. The liquid crystal display according to claim 2, wherein said buffer metal layer is formed from at least one material selected from the group consisting of molybdenum, titanium and tantalum.

5. The liquid crystal display according to claim 1, wherein said storage electrode comprises a transparent conductive material.

6. The liquid crystal display according to claim 1, further comprising a auxiliary storage electrode connected to said storage electrode.

7. The liquid crystal display according to claim 1, further comprising a data line crossed with said gate line and connected to said source electrode by piercing said protective layer.

8. The liquid crystal display according to claim 1, further comprising a gate line in the same layer as said gate electrode and said storage electrode.

10. The liquid crystal display according to claim 5, wherein said transparent conductive material comprises indium tin oxide.

11. The liquid crystal display according to claim 1, wherein said protective layer comprises an organic insulating material.

13. The method according to claim 12, further comprising:

forming a buffer metal layer on said source electrode and said drain electrode.

14. The method according to claim 13, wherein the buffer metal layer reduces contact resistance.

15. The method of according to claim 13, wherein said buffer metal layer is formed from at least one material selected from the group consisting of molybdenum, titanium and tantalum.

16. The method of according to claim 12, wherein said storage electrode is formed of a transparent conductive material.

17. The method of according to claim 16, wherein the transparent conductive material comprises indium tin oxide.

18. The method of according to claim 12, wherein an auxiliary storage electrode is formed connecting to said storage electrode.

19. The method of according to claim 12, wherein said protective layer comprises an organic insulating material.

20. The method of according to claim 19, wherein said organic insulating material is at least one material selected from the group consisting of acrylics, polytetrafluoroethylene, benzocyclobutene, perfluoropolymer resin and perfluorocyclobutane.

9. The liquid crystal display according to claim 31 wherein said buffer metal layer reduces contact resistance.

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

forming a gate electrode and a gate line over a substrate and at the same time forming a storage electrode in a same layer where said gate electrode and said gate line are formed;

forming a gate insulating film to cover said gate electrode, said gate line and said storage electrode;

forming an active layer over said gate insulating film to overlap with said gate electrode;

forming an ohmic contact layer over said active layer;

forming a source electrode and a drain electrode by patterning to expose said active layer;

forming a protective layer over said source electrode and said drain electrode;

forming a contact hole that pierces said protective layer; and

forming a data line crossed with said gate line and connected with said source electrode through said contact hole.