Manufacturing method of electro line for semiconductor device

A method of manufacturing a liquid crystal display device including a Mo/Cu electro line, comprising:

• forming a gate line and a gate electrode, including:
• depositing a molybdenum (Mo) layer on a substrate;
• depositing a copper layer (Cu) on the Mo layer;
• forming a photoresist pattern on the Cu layer;
• etching the Cu layer and the Mo layer using an etchant to form a Mo/Cu electro line, wherein the photoresist pattern is used as a patterning mask;
• and
• removing Mo residue around the Mo/Cu electro line;
• forming a gate insulating layer on the gate line and the gate electrode;
• forming a semiconductor layer on the gate insulating layer over the gate electrode;
• forming a data line, a source electrode and a drain electrode on the semiconductor layer;
• forming a passivation layer on the data line, the source electrode and the drain electrode;
• and
• forming a pixel electrode on the passivation layer.