A display device includes a thin film transistor on a base substrate and a signal wiring electrically connected to the thin film transistor. The signal wiring includes a main conductive layer including copper, and a capping layer including titanium the capping layer overlapping a portion of an upper surface of the main conductive layer. The signal wiring has a taper angle in a range of about 70° to about 90°. A thickness of the capping layer is in a range of about 100 Å to about 300 Å, and a thickness of the main conductive layer is in a range of about 1,000 Å to about 20,000 Å.