ADDITION OF A THIN OVERLAY TO Al FILMS TO STABILIZE THE PROCESS OF MELTING USING SHORT LASER PULSES
Original Publication Date: 1986-Oct-01
Included in the Prior Art Database: 2005-Mar-09
A prior technique [*] has shown that metal layers for VLSI interconnects may be planarized by laser melting and reflow, but this technique does not work well for an Al film because the film absorbs little light. When it melts, the absorption increases and the film overheats. The present technique permits laser melting of an Al by adding a thin layer of Cu on top of the Al film. Introduction Multilevel interconnection on silicon wafers is moving towards finer lines and spaces between lines as lithographic capabilities improve. In the case of the metalization, however, the thickness of the metal lines does not scale in the same way as their area because the increased resistance would be detrimental to performance.