DEPOSITION OF CU FILM ON SIO2 USING A PARTIALLY IONIZED BEAM

Ion bombardment during deposition can significantly modify the film properties. In the partially ionized beam deposition, ions derived from the depositing material, i.e., the self-ions, are used during deposition. Cu films were deposited on SiO2 substrates at room temperature using 1% Cu self-ions with an energy ranging between 0–4 keV. We studied the microstructures of the Cu films using x-ray diffraction and transmission electron microscopy, measured the impurity level inside the films using secondary ion mass spectrometry, and performed the resistivity measurements using a four point probe. The results indicate that there is an optimum ion energy around 2 keV at which, the integrated x-ray intensity ratio I(111)/I(200) reaches its maximum value indicating a strong <111> texture, while the impurity concentration and resisitivity are minimum. The correlation between the structural, compositional and electrical properties are discussed in the framework of Mayadas and Shatzkets's theory of grain boundary resistivity. It was suggested that the electron reflection coefficient at the. grain boundaries is not a constant and is primarily determined by the impurity concentration and orientation of the Cu films which, in turn, depend on the deposition conditions. © 1990, American Vacuum Society. All rights reserved.