Method for fabricating polysilicon thin film transistor with improved electrical characteristics

A method for fabricating a thin film transistor, the method comprising:

• forming a buffer layer on a substrate;
• forming a first amorphous silicon layer on the buffer layer;
• forming a plurality of metal clusters on the first amorphous silicon layer;
• forming a second amorphous silicon layer on the metal clusters including the first amorphous silicon layer;
• simultaneously applying a heat-treatment and an electrical field to crystallize the first and the second amorphous silicon layers, thereby forming first and second polysilicon layers;
• patterning the first polysilicon layer to form a polysilicon island;
• forming a gate electrode, a source electrode, and a drain electrode;
• and
• removing the second polysilicon layer and the metal clusters from the substrate.