TFT substrate and display device having the same

A thin film transistor (TFT) substrate comprising:

• a base substrate;
• a gate wiring formed on the base substrate, the gate wiring including a gate line extending along a first direction and a gate electrode electrically connected to the gate line;
• a gate insulation layer formed on the base substrate to cover the gate wiring;
• an activation layer formed on the gate insulation layer;
• an oxidation-blocking layer formed on the activation layer;
• a data wiring including a data line extending along a second direction substantially perpendicular to the first direction, a source electrode is electrically connected to the data line and a drain electrode separated from the source electrode, the source and drain electrodes being disposed on the oxidation-blocking layer;
• a protection layer covering the data wiring, the protection layer having a contact hole exposing a portion of the drain electrode;
• and
• a pixel electrode formed on the protection layer and electrically connected to the drain electrode through the contact hole,
• wherein at least one of the gate wiring and data wiring includes a three layered structure including a first wiring layer, a third wiring layer, and a second wiring layer intermediate the first and third wiring layers, the first and third wiring layers comprise indium oxide.