Method of forming gate insulation film using plasma method of fabricating poly-silicon thin film transistor using the same

A method of fabricating a poly-silicon thin film transistor, the poly-silicon fabrication method comprising the steps of:

• forming an amorphous silicon film on an insulation substrate;
• patterning the amorphous silicon film, to thereby form a semiconductor layer;
• processing the semiconductor layer made of the amorphous silicon film by an oxygen plasma method, and oxidizing the silicon surface, to thereby form a first silicon oxide film;
• mixing gas with silicon and depositing a second silicon oxide film on the first silicon oxide film by a PECVD (Plasma Enhanced Chemical Vapor Deposition) method;
• forming a metal film for forming a gate electrode on an insulation substrate including the semiconductor layer;
• sequentially patterning the gate electrode forming metal film, the second silicon oxide film and the first silicon oxide film, to thereby form a gate electrode and a gate insulation film;
• ion-injecting impurities onto the substrate to thereby define a source region and a drain region;
• and
• crystallizing the amorphous silicon in the semiconductor layer into poly-silicon through heat treatment of a MIC (Metal Induced Crystallization) method and a MILC (Metal Induced Lateral Crystallization) method using a crystallization expediting metal film.