Damascene copper integration issues in SiCOH dielectric

This paper discusses the integration of damascene copper in low-k SiCOH intermetal dielectric. BEOL wiring yields are dominated by wire and via opens, due primarily to blocked liner deposition; and to wire shorts, due primarily to Cu CMP scratches. Wire resistance and capacitance variability are primarily due to wafer-to-wafer process variability, which is 1.5 to 2 times greater than within-wafer variability. In general, 90nm SiCOH BEOL wiring variability and yield limiters are very comparable to previous generation oxide or FSG-based Cu wiring.