EFFECTS OF THE ANNEALING IN AR AND H-2 AR AMBIENTS ON THE MICROSTRUCTURE AND THE ELECTRICAL-RESISTIVITY OF THE COPPER FILM PREPARED BY CHEMICAL-VAPOR-DEPOSITION/

The copper films with a thickness of 600 nm were prepared on TiN at 18 0 degrees C under O.5 Torr using chemical vapor deposition (CVD) metho d. The deposited films were subjected to be annealed at various temper atures (350-550 degrees C) in Ar and H-2(10%)/Ar ambients. The changes of the microstructures and the electrical resistivity after annealing were investigated. H-2(10%)/Ar was more effective than Ar as an ambie nt gas for the post annealing of the copper films, because smaller res istivity and larger grain size of the annealed film was given. The res istivity of the annealed film decreased, and the grain size increased with the annealing temperature. However, 550 degrees C is found to be inappropriate as the annealing temperature, because the out-diffusion of silicon through the TiN layer was observed. Upon annealing at 450 d egrees C for 30 min in an H-2(10%)/Ar ambient, the grain size of the f ilm increased from 148 nm to 219 nm, and the resistivity decreased fro m 2.35 mu Omega . cm to 2.12 mu Omega . cm.