Agglomeration of copper thin film in Cu/Ta/Si structure

Copper agglomeration in Cu(100nm)/Ta(50nm)/Si structure deposited by ion beam deposition was examined. Copper thin films were annealed at 650°C for 1 to 60 min in hydrogen atmosphere. The surface morphology, crystalline microstructure and electrical resistivity were investigated by field-emission scanning electron microscopy, X-ray diffraction and Van der Pauw method, respectively. Experimental results revealed that nucleation and growth of voids ocurred in the copper film annealed for 5 min. Further annealing made the film a connected island structure and then isolated island structure.