Thin film transistor for liquid crystal display device having a semiconductor layer's width smaller than a width of the gate, drain and source electrodes

摘要

A thin film transistor for liquid crystal display device including a gate electrode 42 formed on a transparent substrate 41, an insulation layer 43 formed to cover the upper surface of the transparent substrate and the gate electrode, a semiconductor layer 46 formed on the insulating layer in confrontation with the gate electrode, an etching stopper layer 44 formed on the semiconductor layer and a source electrode 49 and a drain electrode 50 disposed adjacent to each other in confrontation on both the sides of the semiconductor layer over the etching stopper layer, the semiconductor layer and the insulation layer is arranged such that the gate electrode is formed to such a size as to conceal the semiconductor layer from the transparent substrate side and the line width of the source electrode and the drain electrode is made larger than the width of the semiconductor layer along the same direction as the line width. With this arrangement, there can be provided a thin film transistor for liquid crystal display device capable of suppressing the leak current of the semiconductor layer and lowering the off-current of the thin film transistor and a liquid crystal display device including the thin film transistor.