Thin film transistor and display substrate having the same

A display substrate, comprising:

• a base substrate;
• a semiconductor active layer disposed on the base substrate;
• a first conductive pattern group insulated from the semiconductor active layer and including at least a gate electrode;
• a second conductive pattern group insulated from the first conductive pattern group and including at least a source electrode, a drain electrode, and a data pad;
• and
• an organic light emitting device connected to the drain electrode;
• the second conductive pattern group comprising a first conductive layer and a second conductive layer disposed on the first conductive layer to prevent the first conductive layer from being corroded and oxidized.

A display substrate comprising:

• a base substrate;
• a first thin film transistor disposed on the base substrate;
• a second thin film transistor disposed on the base substrate and electrically connected to the first thin film transistor;
• and
• an organic light emitting device connected to the second thin film transistor;
• wherein the first thin film transistor comprises a first semiconductor active layer, a first gate electrode, a first source electrode, and a first drain electrode;
• wherein the second thin film transistor comprises a second semiconductor active layer, a second gate electrode, a second source electrode, and a second drain electrode;
• wherein the first source electrode, the first drain electrode, the second source electrode, and the second drain electrode are disposed on a same layer;
• and
• wherein each of the first source electrode, the first drain electrode, the second source electrode, and the second drain electrode comprises:
• a first conductive layer that includes one of copper, a copper alloy, aluminum, and an aluminum alloy;
• and
• a second conductive layer disposed on the first conductive layer and including a molybdenum-nickel alloy.