FSG process development for copper/damascene technology

We report process characterization for a fluorosilicate glass (FSG), developed specifically for copper/damascene, where both the via and the line are embedded in FSG (K/spl les/3.65) at 6 levels. We compare FSG films deposited in both high density plasma (HDP) and PECVD reactors, for K values within the range 3.50-3.70; PECVD FSG films absorb more water than HDP films. Several issues important in producing a manufacturable FSG technology are noted: FSG film thickness; deposition temperature and substrate dopant concentration; in-film fluorine concentration; and FSG/silicon nitride defectivity.