STRUCTURES AND PROPERTIES OF COPPER THIN-FILMS PREPARED BY ION-BEAM-ASSISTED DEPOSITION

Copper thin films were prepared by ion beam assisted deposition (IBAD) technique, to perform a systematic investigation on the effect of ion bombardment with respect to the structural modification and the elect rical properties of the Rims. The films were deposited under the argon ion bombardment with energies between 75 and 675 ey. The atomic densi ty of the films deposited on Si substrates strongly depended on the de position rate rather than the energy or the current of the ion beams. Under the same deposition rate, the atomic density gradually decreased with an increase of the ion energy. As for the films on SiO2 substrat es, however, the atomic densities were improved with increasing the ar rival rate ratio and the ion energy. X-ray diffraction analysis showed that the film structures were modified to have (111) preferred orient ation and the films had larger vertical grain sizes with increasing th e arrival rate ratio and the ion energy. These modifications were also most significant for the films deposited on SiO2 substrates. Electric al resistivity strongly depended on the argon concentration in the fil ms, while less depended on the crystallinity. The increase of the elec trical resistivity for the films on Si substrates was larger than thos e on SiO, substrates. It was suggested that the lateral grain size, wh ich dominates the electrical resistivity, reduced with an increase of the arrival rate ratio and the ion energy. The results could be summar ized as the structure of the films prepared by IBAD technique became c olumnar and the electrical resistivity had a strong correlation with t he argon concentration.