THIN-FILM TRANSISTOR FOR LIQUID CRYSTAL DISPLAY DEVICE AND ITS PRODUCTION

PURPOSE:To provide the thin-film transistor(TFT) for a liquid crystal display device at a good yield without display defects by simple stages by preventing the overhang by ohmic barrier layers and enhancing the reliability of connection to display electrodes. CONSTITUTION:A data wiring consisting of a low-resistance material forms a two-layered structure consisting of a first layer data wiring 30c which is a main signal wiring layer 30 and a second layer data wiring 31c which is a battery reaction preventive layer 31. The drain electrode and source electrode of the TFT form a three-layered structure consisting of a first layer 28a of the source electrode and first layer 28b of the drain electrode which constitute the ohmic barrier layers 28 with semiconductor layers 27a, 27b, a second layer 30a of the source electrode and second layer 30b of the drain electrode which are formed flush with the first layer data wiring 30c and a third layer 31a of the source electrode and third layer 31b of the drain electrode which are formed flush with the second layer data wiring 31c.