Low Resistivity Mo-W Alloy for A-Si Tft Gate Electrode

Among various requirements for the a-Si TFT-LCD gate electrode, low resistivity is becoming more emphasized with the increase of display size and information content as well as process feasibility. We have developed a low resistivity Mo-W alloy as a material for gate buslines. The Mo-W film was formed by DC magnetron sputtering using Ar or Kr as the working gas. The resistivity of the fabricated film was 16 μΩ-cm when deposited with Ar, and decreased to a value as low as 13 μΩ-cm with Kr, which was less than a half that of the conventional Mo-Ta film. Inverted staggered a-Si TFTs having Mo-W gate electrodes formed with Kr were fabricated, and good transfer performance with thermal- and electrical stability was obtained. The applicability of the new alloy to LCDs with large area and high resolution was shown.