Solution-Based Precursor Delivery for Copper CVD

Abstract

AbstractWe have measured growth rates and film properties for copper CVD using Cu(hfac)2 dissolved in isopropanol as the precursor delivery method. This approach offers the convenience and control associated with liquid precursor delivery, while avoiding the need to handle the precursor at its high melting point. The method provides similar growth rates to those observed using conventional delivery by solid sublimation, with the additional benefit that these growth rates are achieved using a much lower partial pressure of precursor in the reactor. The growth rate is nearly independent of the partial pressure of Cu(hfac)2, isopropanol, and H2 over the range of operating conditions examined. The film morphology and resistivity are also largely unaffected by the deposition conditions. These results strongly suggest that the mechanism proceeds via an adsorbed intermediate formed by the reaction of Cu(hfac)2 and isopropanol, and that the surface is nearly fully saturated by this intermediate.