METHOD FOR MANUFACTURING THIN FILM TRANSISTORS

摘要

PURPOSE: A fabrication method of thin film transistors is provided to reduce ON-current and improve threshold voltage by making the distribution of electric field to uniform. CONSTITUTION: The thin film transistor formation method comprises the steps of: forming a gate electrode(21) on a semiconductor substrate(20); forming a first oxide layer(22) and fattening the first oxide layer(22) by CMP; exposing a portion of the gate electrode(21) by wet-etching the first oxide layer(22); forming a nitride spacer(23) at both sidewalls of the exposed gate electrode; forming a first oxide pattern connected between the nitride spacer(23) and the semiconductor substrate(20) by etching the first oxide layer(22) using the gate electrode and the nitride spacer as an etching stopper; forming a gate oxide(24) on the resultant structure; and forming a polysilicon layer on the gate oxide and forming a source(25A), a drain(25B) and a channel(25C) by selective ion-implanting to the polysilicon layer.