Method of fabricating CMOS thin film transistor

A method of fabricating a CMOS thin film transistor, comprising the steps of:

• forming a first active layer at a first area of a transparent substrate;
• forming a second active layer at a second area of said transparent substrate;
• forming a first gate insulating film on a middle portion of said first active layer such that ends of said first active layer are exposed;
• forming a second gate insulating film on a middle portion of said second active layer such that ends of said second active layer are exposed;
• ion-doping said ends of said first active layer and said ends of said second active layer with a first conductive impurity at a first energy and at a first concentration, wherein first high-concentrated impurity areas are formed on said ends of said first active layer, and wherein second high-concentrated impurity areas are formed on said ends of said second active layer;
• forming a photoresist pattern over said first transistor area;
• and
• ion-doping said second high-concentrated impurity areas with a second impurity at a second energy that is greater than said first energy and at a second concentration that is greater than said first concentration so as to form third high-concentrated impurity areas;
• wherein said first impurity and said second impurity are opposite types.

A CMOS thin film transistor, comprising:

• a first active layer on a substrate, said first active layer having end portions that are ion-doped with a first conductive impurity of a first polarity;
• a first gate insulating film on a middle portion of said first active layer;
• a second active layer on said substrate, said second active layer having end portions that are ion-doped with said first conductive impurity and with a second conductive impurity of an opposite polarity, wherein said second conductive impurity changes the doping of said end portions from said first polarity to said second polarity;
• a second gate insulating film on a middle portion of said second active layer;
• a first gate over said first gate insulating film;
• and
• a second gate over said second gate insulation film.