Thin film transistor, manufacturing method of thin film transistor, and organic light emitting diode display including the same

A manufacturing method of a thin film transistor, the method comprising:

• forming a buffer layer on a substrate;
• forming a semiconductor layer on the buffer layer;
• forming a gate insulating pattern on the semiconductor layer;
• forming a gate metal layer covering the gate insulating pattern and the substrate;
• moving residual metal catalysts in the semiconductor layer to the gate metal layer that contacts the semiconductor layer by performing gettering heat treatment on the semiconductor layer;
• forming a gate electrode by patterning the gate metal layer;
• forming an interlayer insulating layer covering the gate electrode, the gate insulating pattern, and the substrate;
• forming a contact hole exposing a source area and a drain area of the semiconductor layer and an opening exposing the gate electrode on an undoped channel area of the semiconductor layer by patterning the interlayer insulating layer and the gate insulating pattern;
• and forming a source electrode connected with the source area and a drain electrode connected with the drain area of the semiconductor layer on the interlayer insulating layer.

An organic light emitting diode (OLED) display comprising:

• a thin film transistor including:
• a substrate,
• a buffer layer on the substrate,
• a semiconductor layer on the buffer layer,
• a gate insulating pattern on the semiconductor layer,
• a gate electrode on the gate insulating pattern,
• an interlayer insulating layer covering the gate electrode and the gate insulating pattern, the interlayer insulating layer having a contact hole and an opening extending therethrough, the contact hole exposing a source area and a drain area of the semiconductor layer, and the opening exposing an undoped channel area of the semiconductor layer, and
• a source electrode and a drain electrode on the interlayer insulating layer, the source electrode being connected with the source area and the drain electrode being connected with the drain area of the semiconductor layer;
• a pixel electrode on the thin film transistor and connected with the thin film transistor;
• an organic light emitting member on the pixel electrode;
• and
• a common electrode on the organic light emitting member.