MANUFACTURING METHOD OF THIN FILM TRANSISTOR BY LOCAL-DOPPONG AND APPARATUS BY THE SAME

摘要

A method for fabricating a thin film transistor using local doping is provided to simplify fabrication of a channel region and a source/drain electrode formation process by using a doped transparent metal oxide semiconductor layer as a source/drain electrode and a transparent pixel electrode wherein an undoped transparent metal oxide layer is not used as a channel region. A buffer layer(12) can be formed on a substrate(11). A transparent metal oxide semiconductor(13) is formed on the substrate, and a passivation layer is formed to isolate the surface of the transparent metal oxide semiconductor from an external air. The transparent metal oxide semiconductor and the passivation layer are simultaneously patterned. The passivation layer can be etched. A gate insulation layer is formed on the transparent metal oxide semiconductor. A gate electrode material is deposited on the gate insulation layer and is patterned to form a gate electrode. High density impurities are locally doped into the transparent metal oxide semiconductor except a vertical portion under the gate electrode to dope high density impurities by a direct ion implantation process or a diffusion process. The semiconductor part formed by doping of impurities becomes a source or a drain, and one of the source or drain is formed as a transparent pixel electrode.