Void free Cu or Cu alloy interconnects are formed by annealing at superatmospheric pressure after metallization. Embodiments include filling a damascene opening in a dielectric layer with Cu or a Cu alloy and heat treating in a chamber at a pressure of about 2 atmospheres to about 750 atmospheres....http://www.google.de/patents/US6121141?utm_source=gb-gplus-sharePatent US6121141 - Method of forming a void free copper interconnects
