Mo-capped Al-Nd alloy for both gate and data bus lines of liquid crystal displays

Aluminum-neodymium (AI-Nd) alloy and molybdenum (Mo)-capped structures were applied to both gate and data bus lines of liquid crystal displays (LCD). We investigated the hillock resistance and electrical properties of Al-Nd alloys. Their structures were studied by cross-sectional transmission electron microscopy (TEM) and SEM. Adding 2 at.% Nd to Al effectively prevented the Al film from forming hillock and whisker. The electrical resistivity varied with the annealing temperature after deposition: the resistivity was 4.3 mu Omega cm with annealing at 350 degreesC and 10.0 mu Omega cm with annealing at 250 degreesC. Mo is used not only to suppress hillocks, but also for taper etching of lines and as a contact layer with other materials. We investigated the effects of adding Nd to Al, and found that the Nd addition improved the step coverage, thermal resistance, patternability, and mechanical strength of the lines. By applying a common structure and metals for both gate and data bus lines, we could increase the productivity of TFT-LCDs. (C) 2001 Elsevier Science B.V. All rights reserved.