Etchant and method for fabricating electric device including thin film transistor using the same

1. A method of fabricating an electric device comprising a thin film transistor substrate, comprising:

forming a multi-layered film by depositing titanium (Ti) or a titanium alloy (Ti alloy), and copper (Cu);

forming a selective mask by a photoresist method on the multi-layered film; and

subjecting the masked multi-layered film to an etchant including a fluorine ion (F − ) source, hydrogen peroxide (H 2 O 2 ), a sulfate, a phosphate, an azole-based compound, and a solvent to form a pattern;

wherein the azole-based compound is selected from the group consisting of tolyltriazole and alkylimidazole wherein the alkyl is a C 1 to C 7 alkyl, and combinations thereof.

2. The method of claim 1 , wherein the patterned multi-layered film is used for a gate electrode of a thin film transistor.

3. The method of claim 1 , wherein the patterned multi-layered film is used for a source or drain electrode of a thin film transistor.

4. The method of claim 1 , wherein the substrate including a thin film transistor is applied to a thin film transistor-liquid crystal display (LCD).

5. The method of claim 1 , wherein the substrate including a thin film transistor is applied to an organic light emitting diode (OLED) display.

6. The method of claim 1 , wherein the multi-layered film comprises a copper (Cu) layer, and a titanium (Ti) or titanium alloy layer.

7. An etchant comprising:

a fluorine ion (F − ) source;

hydrogen peroxide (H 2 O 2 );

a sulfate;

a phosphate;

an azole-based compound; and

a solvent

wherein the azole-based compound is selected from the group consisting of tolyltriazole and alkylimidazole wherein the alkyl is a C 1 to C 7 alkyl, and combinations thereof;

wherein the fluorine ion source is present at a concentration of from about 0.01 wt % to about 10 wt %, the hydrogen peroxide is present at a concentration of from about 1 wt % to about 20 wt %, the sulfate is present at a concentration of from about 0.1 wt % to about 10 wt %, the phosphate is present at a concentration of from about 0.1 wt % to about 10 wt %, the azole-based compound is present at a concentration of from about 0.01 wt % to about 5 wt %, and the solvent is present in a balance amount; and

wherein the etchant etches a multi-layer comprising copper/titanium or a copper/titanium alloy.

8. The etchant of claim 7 , wherein the fluorine ion (F − ) source is selected from the group consisting of hydrogen fluoride (HF), ammonium fluoride (NH 4 F), ammonium hydrogen fluoride (NH 4 HF 2 ), potassium fluoride (KF), sodium fluoride (NaF), and combinations thereof.

9. The etchant of claim 7 , wherein the sulfate is a compound selected from of the group consisting of A 2 SO 4 , AHSO 4 , BSO 4 and combinations thereof, wherein A is selected from the group consisting of an alkali metal, an ammonium ion (NH 4 − ), and combinations thereof, and wherein B is an alkaline-earth metal.

10. The etchant of claim 7 , wherein the phosphate is a compound of the formula D x H y PO 4 wherein x and y are integers from 0 to 3, wherein x+y=3, and wherein D is selected from the group consisting of an alkali metal, an alkaline-earth metal, an ammonium ion (NH 4 − ), and combinations thereof.

11. The etchant of claim 7 , wherein the solvent is purified water or de-ionized water.

12. The etchant of claim 7 , wherein the multi-layered film comprises a copper (Cu) layer, and a titanium (Ti) or titanium alloy layer.