Thin film transistor manufacturing method, thin film transistor and display device using the same

Abstract

A thin film transistor manufacturing method includes the steps of: forming a gate electrode, gate insulating film and amorphous silicon film in succession on an insulating substrate; forming a channel protective film only in the region which will serve as a channel region of the amorphous silicon film; and forming an n-plus silicon film and metal layer on top of the channel protective film and amorphous silicon film in succession. The method further includes the step of patterning the amorphous silicon film and n-plus silicon film to selectively leave the region associated with source and drain electrodes, using the channel protective film as an etching stopper to selectively remove the region of the n-plus silicon film and metal layer associated with the channel region so as to form source and drain regions from the n-plus silicon film and also form source and drain electrodes from the metal layer.