The diffusion barrier properties of as-deposited Ta without ion bombardment, and of Ta which was deposited during ion bombardment, were investigated in a Cu/Ta/Si contact system by using Auger electron spectroscopy, X-ray diffractometry, optical microscopy, transmission electron microscopy, and sheet resistivity methods. It was found that ion bombardment during deposition affected microstructural parameters such as the packing density of grain boundaries, the grain size and the preferred orientation of Ta grains. Films which were deposited at the same time as 150eV ions (0.13mA/cm2) exhibited an increased packing density of grain boundaries, a low resistivity and a preferred orientation.

B.S.Kang, S.M.Lee, J.S.Kwak, D.S.Yoon, H.K.Baik: Journal of the Electrochemical Society, 1997, 144[5], 1807-12