METHOD OF FABRICATING POLYSILICON THIN FILM TRANSISTOR

摘要

PURPOSE: A method of fabricating a polysilicon thin film transistor is provided to increase the grain size of polysilicon forming a channel of a polysilicon thin film transistor to reduce grain boundary density. CONSTITUTION: An amorphous silicon thin film is formed on a wafer on which an oxide layer is formed or a glass substrate, and patterned to form an amorphous silicon thin film active region. A photoresist pattern is formed on the amorphous silicon thin film, and a nickel thin film is formed on the silicon thin film and photoresist pattern. The photoresist pattern and the nickel thin film are removed by lift-off to form a nickel pattern. The amorphous silicon thin film is annealed to form a polysilicon thin film. Excimer laser is irradiated on the polysilicon thin film. The nickel thin film is removed, and then a silicon oxide layer is deposited. A gate electrode pattern is formed on the polysilicon thin film and silicon oxide layer, and the silicon oxide layer formed between the polysilicon thin film and gate electrode pattern is patterned and the photoresist pattern is removed. The polysilicon thin film is doped with ions to form gate, source and drain electrodes and the doped ions are activated.