Organic light emitting diode display having thin film transistor substrate using oxide semiconductor

An organic light emitting diode (OLED) display comprising:

• a gate electrode formed on a substrate;
• a gate insulating layer formed on the gate electrode;
• a semiconductor layer formed on the gate insulating layer to overlap with the gate electrode, and including a channel area and source and drain areas which extend from the channel area to lateral end portions, respectively, and are conductorized;
• an etch stopper formed on the channel area and exposing the source area and the drain area;
• a source electrode contacting portions of the exposed source area;
• and
• a drain electrode contacting portions of the exposed drain area,
• wherein the source electrode and the drain electrode each include a first metal layer and a second metal layer stacked on the first metal layer,
• wherein the etch stopper formed on the channel area does not contact the source and drain electrodes,
• wherein the first metal layer and second metal layers of the source and drain electrodes have a substantially same shape and size, respectively, and
• wherein the conductorized source and drain areas extend from a top surface of the semiconductor layer to a bottom surface of the semiconductor layer.