Realization of Sequential Epitaxial Growth of Cu/HfN Bilayered Films on (111) and (001) Si

Abstract

Cu films were deposited on epitaxial HfN/Si systems using a dc magnetron sputtering system without breaking the vacuum. Crystal orientation of Cu films was investigated by X-ray diffraction (XRD) and X-ray pole figure analyses. Epitaxial growth of (111) and (110) Cu was confirmed on epitaxial (111) and (001) HfN films, respectively. Surface morphology of HfN/Si and Cu/HfN/Si systems was examined by atomic force microscopy (AFM). Both epitaxial HfN films have quite flat surfaces, in spite of the difference in their orientational planes. However, the surface roughness of (110) Cu film on (001) HfN was estimated to be half of that of (111) Cu film on (111) HfN. It is revealed that the difference in surface morphology between epitaxial (111) and (110) Cu is ascribed to the difference between factors governing the epitaxial growth at the Cu/HfN interface.