Thin film transistor and method of fabricating the same

A method of fabricating a thin film transistor, comprising:

• preparing an insulating substrate;
• forming an amorphous silicon layer on the substrate;
• forming a filtering oxide layer and a capping layer on the amorphous silicon layer;
• depositing a metal catalyst on the capping layer;
• performing a first heat-treatment to diffuse the metal catalyst to move to an interface between the filtering oxide layer and the amorphous silicon layer through the capping layer and the filtering oxide layer;
• performing a second heat-treatment to crystallize the amorphous silicon layer by the diffused metal catalyst to form a polysilicon layer;
• removing the capping layer;
• patterning the filtering oxide layer and the polysilicon layer to form a semiconductor layer;
• forming a gate insulating layer above the substrate;
• and
• forming a gate electrode above the substrate, and forming an interlayer insulator and a source/drain electrode.