Method of fabricating polysilicon layer, thin film transistor, organic light emitting diode display device including the same, and method of fabricating the same

A thin film transistor comprising:

• a substrate;
• a buffer layer disposed on the substrate and comprising a metal catalyst therein;
• a semiconductor layer disposed on the buffer layer;
• a source electrode and a drain electrode disposed on respective sides of the semiconductor layer so as to expose a portion of the semiconductor layer;
• a gate insulating layer disposed on the substrate, the source electrode and the drain electrode;
• a gate electrode corresponding to the semiconductor layer and disposed on the gate insulating layer;
• and
• a metal silicide disposed between the buffer layer and the semiconductor layer,
• wherein the buffer layer is surface treated with ozone, such that the upper surface of the buffer layer is oxidized and thereby configured to control an amount of the metal catalyst that is diffused from the buffer layer and converted into the metal silicide.

An organic light emitting diode display device comprising:

• a substrate;
• a buffer layer disposed on the substrate and comprising a metal catalyst therein;
• a semiconductor layer disposed on the buffer layer;
• a gate insulating layer disposed on the substrate including the semiconductor layer;
• a gate electrode disposed on the gate insulating layer;
• a source electrode and a drain electrode both electrically connected to the semiconductor layer;
• and
• a metal silicide disposed between the buffer layer and the semiconductor layer,
• wherein the buffer layer is surface treated with ozone, such that the upper surface of the buffer layer is oxidized and thereby configured to control an amount of the metal catalyst that is diffused from the buffer layer and converted into the metal silicide.