THIN FILM FIELD EFFECT TRANSISTOR AND DISPLAY DEVICE USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a thin film field effect transistor having high mobility and showing a high on/off-ratio and to provide a display device using the transistor. SOLUTION: In the thin film field effect transistor, at least a gate electrode 2, a gate insulating film 3, an active layer 4, a source electrode 5-1 and a drain electrode 5-2 are installed on a substrate 1. The active layer is an oxide semiconductor layer. A resistance layer 6 formed of the oxide semiconductor layer is arranged between the active layer and at least the source electrode or the drain electrode. The electrical conductivity of the active layer is not lower than 10-4Scm-1to lower than 102Scm-1, a rate (electrical conductivity of active layer/electrical conductivity of resistance layer) of the electrical conductivity of the active layer with respect to the electrical conductivity of the resistance layer is not smaller than 101to not larger than 1010, and face-sides which are brought into contact with the resistance layer of at least the source electrode or the drain electrode are Ti or Ti alloy layers 8-1 and 8-2. COPYRIGHT: (C)2010,JPO&INPIT