Prodn. of a thin film transistor comprises: (a) forming a gate electrode (12) on a substrate (11); (b) forming a gate insulating layer (14) on the gate electrode (12); (c) applying a semiconductor layer (15) on the gate insulating layer (14). (d) anisotropically etching by back etching the semiconductor layer (15) to obtain side walls (15a) of semiconductor material on both side surfaces of the gate electrode (2); and (e) forming a source and a drain transition by selectively implanting ions into the side walls (15a). Also claimed are similar processes for the prodn. of the transistor.
