PROGRESS TOWARD EXCIMER-LASER METAL PLANARIZATION AND VIA HOLE FILLING USING INSITU MONITORING

Future high-density interconnect and multilevel metalization schemes w ill require planarized dielectric and metalization layers in order to satisfy stringent photolithographic and step coverage requirements. Ex cimer lasers represent one possible solution for metal planarization. Pulsed excimer lasers irradiate the metal layer with very short (pulse full width at half maximum FWHM almost-equal-to 25-40 ns) highly ener getic (up to 10 J cm-2) homogenized beams to melt an absorbing metal o verlayer. While molten, the surface is driven flat due to the surface tension and low viscosity of metals. In this work we review our excime r laser planarization work, introduce the concept of in-situ monitorin g to design a high-aspect-ratio contact hole filling planarization pro cess, and summarize prospects for future work.