MANUFACTURING METHOD OF THIN FILM TRANSISTOR

PURPOSE: A method for manufacturing a thin film transistor is provided to prevent a band bending in an interface between a protection layer and a channel region of a semiconductor layer by processing the channel region of a semiconductor layer with plasma using gas with III group elements or V group elements. CONSTITUTION: A first metal layer is laminated on a substrate(S100). A gate electrode is formed by using a first mask(S110). A gate insulation layer is formed on the front side of the substrate including the gate electrode. An amorphous silicon layer, a doped silicon layer, and a second metal layer are laminated on the gate insulation layer(S130). A semiconductor layer, an ohmic contact layer, a source electrode, and a drain electrode are formed by patterning the amorphous silicon layer, the doped silicon layer, and the second metal layer with a second mask. A channel region of the semiconductor layer is processed with plasma(S150). A protection layer is formed to cover the channel region processed with plasma(S160). [Reference numerals] (S100) Laminating a first metal layer on a substrate; (S110) Forming a gate electrode using a first mask; (S120) Forming a gate insulation layer; (S130) Laminating an amorphous silicon layer, a doped silicon layer, and a first metal layer on a gate insulation layer; (S140) Forming a semiconductor layer, an ohmic contact layer and a source/drain electrode by patterning an amorphous silicon layer, a doped silicon layer, and a second metal layer; (S150) Plasma process in a channel region of a semiconductor; (S160) Forming a protection layer