METHOD FOR FABRICATING TFT

摘要

PURPOSE: A method for fabricating a TFT(Thin Film Transistor) is provided to improve a step coverage by forming a trench bottom gate TFT. CONSTITUTION: An oxide layer(22) is deposited on a silicon substrate(21). A trench is formed by performing an etch process. A polysilicon layer is formed by depositing a polysilicon on the oxide layer(22) and the trench. A trench gate line(23) is formed by etching back the polysilicon layer. A gate insulating layer(24) is deposited on the oxide layer(22) and the gate line(23). A body polysilicon is deposited thereon. A polysilicon layer is formed by performing an annealing process the body polysilicon. An ion implant process is performed to implant ions into the polysilicon layer. A photoresist pattern is formed by performing a photo mask process. A drain junction is formed by performing an ion implant process. A source/drain junction(211) is formed by implanting ions.