Composition for etching double metal layer, method of fabricating array substrate using the composition, and method of forming double metal line using the composition

1. A method of fabricating an array substrate for a liquid crystal display device, comprising:

forming a first double metal layer including aluminum neodymium (AlNd) and molybdenum (Mo) on a substrate;

forming a first photoresist pattern on the first double metal layer;

etching the first double metal layer with a composition including about 63.5% to about 64.5% by weight of a phosphoric acid, about 8% to about 9% by weight of a nitric acid, about 8% to about 12% by weight of an acetic acid, and about 1% to about 4% by weight of a fluoric anionic surfactant to form a gate line and a gate electrode without an AlNd residue and a Mo tail;

forming a gate insulating layer on the gate line and the gate electrode;

forming a semiconductor layer on the gate insulating layer at a portion corresponding to the gate electrode;

forming a data line on the gate insulating layer and source/drain electrodes on the semiconductor layer;

forming a passivation layer on the data line and the source and drain electrodes, the passivation layer has a drain contact hole exposing the drain electrode; and

forming a pixel electrode on the passivation layer, the pixel electrode connected to the drain electrode through the drain contact hole.

2. The method according to claim 1 , wherein the phosphoric acid has a content of about 64% by weight.

3. The method according to claim 1 , wherein the nitric acid has a content of about 8.5% by weight.

4. The method according to claim 1 , wherein the acetic acid has a content of about 10% by weight.

5. The method according to claim 1 , wherein the first double metal layer includes a lower molybdenum (Mo) layer and an upper aluminum neodymium (AlNd) layer.

6. The method according to claim 1 , wherein the first double metal layer includes a lower aluminum neodymium (AlNd) layer and an upper molybdenum (Mo) layer.

7. The method according to claim 1 , wherein forming the data line and the source/drain electrodes, comprises:

forming a second double metal layer including aluminum neodymium (AlNd) and molybdenum (Mo) on the gate insulating layer;

forming a second photoresist pattern on the second double metal layer; and

etching the second double metal layer with the composition.

8. The method according to claim 1 , wherein the uniform edge slope has an angle of about 42° with respect to the substrate.

9. A method of forming a double metal line, comprising:

forming a double metal layer including aluminum neodymium (AlNd) and molybdenum (Mo) on an insulating layer;

forming a photoresist pattern on the double metal layer; and

etching the double metal layer with a composition including about 63.5% to about 64.5% by weight of a phosphoric acid, about 8% to about 9% by weight of a nitric acid, about 8% to about 12% by weight of an acetic acid, and about 1% to about 4% by weight of a fluoric anionic surfactant to form the double metal line without an AlNd residue and a Mo tail.

10. The method according to claim 9 , wherein the phosphoric acid has a content of about 64% by weight.

11. The method according to claim 9 , wherein the nitric acid has a content of about 8.5% by weight.

12. The method according to claim 9 , wherein the acetic acid has a content of about 10% by weight.

13. The method according to claim 9 , wherein the fluoric anionic surfactant has a content of about 3% by weight.