MANUFACTURE OF THIN FILM TRANSISTOR

摘要

PURPOSE:To enable a dope area where impurities are introduced to be formed at an area away from the gate insulation film and to obtain a thin film transistor which allows threshold to be controlled easily directly below the protection film excluding the area near the interface between a non-doped amorphous Si layer and a gate insulation film. CONSTITUTION:After laminating an insulation film consisting of an gate electrode G, a gate insulation film 1, a doped a-Si:H layer 2, and a protection film, unneeded part of this protection insulation film is removed to allow a protection film 3 to remain only directly on the gate electrode G. Then, a source electrode S and a drain electrode D are formed sandwiching the protection film 3. Then, the ion implantation of specified impurities is performed with the source electrode S and the drain electrode D being a mask. Then, annealing is performed to it to allow a doped area 7 to be formed at a part separated from the gate insulation film 1 excluding the channel formation area near the interface of the undoped a-Si:H layer 2 and the gate insulation film 1.