Thin Solid Films, Vol.599, 31-36, 2016
Feasibility study on the use of Cu(Co) alloy for barrierless copper metallization
In the present study, the properties of Cu(Co) alloy films were studied to evaluate their potential use as alloying elements for copper metallization. The Cu(Co) films were deposited on SiO2/Si substrates using magnetron sputtering technique. Cu(Co)/SiO2/Si structures were subsequently annealed in the temperature range of 300-600 degrees C to determine the diffusion barrier characteristics of the films. Thereafter samples were characterized using four-point probe measurements, X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron and transmission electron microscopy. It was found that the Cu(Co) films were preferentially orientated at (111) plane. No copper silicide was detected in the Cu(Co) films annealed up to 500 degrees C. A Co-containing thin layer was found at the Cu (Co)/SiO2 interface. In addition, well-defined interfaces were obtained for the sample annealed at 500 degrees C. There was no evidence of inter-diffusion between Cu and the substrate. (C) 2015 Elsevier B.V. All rights reserved.