Characterization of laser planarized aluminum for submicron double level metal CMOS circuits

A high-power pulsed laser has been used to flow aluminum into vias to provide a planarized surface. It is shown that laser planarization is a viable means of filling high-aspect-ratio vias for submicron geometries and can be used without degrading device performance or reliability. The current carrying capability of laser-annealed metal lines is equal to that of nonannealed lines, showing that they can be reliably used as interconnects in high-performance circuits. A high-density digital CMOS double-metal circuit based on 1 mu m design rules has been fabricated using this technique. The planarity of the Al lines in vias and over steps is excellent compared to that for a standard metal.<>