THIN FILM TRANSISTOR DEVICE, ITS MANUFACTURE, AND LIQUID CRYSTAL DISPLAY DEVICE

摘要

PROBLEM TO BE SOLVED: To easily obtain an LDD having a desired length by forming the cross section of the first layer on a channel area side of a gate wiring layer having a two-layer structure in a forwardly tapered shape and that of the second layer on a surface side in a reversely tapered shape. SOLUTION: On a semiconductor layer 26, a TFT 17 forming a gate wiring layer having such a two-layer structure that the cross section of the first layer 28a composed of a first gate metal film is forwardly tapered at 30 deg. and the cross section of a second layer 28b composed of a second gate metal film is reversely tapered at 30 deg. and made of a molybdenum-tungsten alloy is provided. In addition, an auxiliary capacitive line 30 is formed flush with the wiring layer 28. Therefore, the number of manufacturing processes of a thin film transistor device can be reduced and a LDD having a desired length can be obtained easily without causing length dispersion, because ion doping can be performed simultaneously on an LDD area and a source-drain area in a self-aligning way through one time of doping process.