REMOTE PLASMA CHEMICAL VAPOR-DEPOSITION OF COPPER FOR APPLICATIONS IN MICROELECTRONICS

High-quality copper films were deposited from the beta-diketonate precursor copper(II) (hexafluoroacetylacetonato), Cu(hfa2), using a remote plasma chemical vapor deposition (RPCVD) process which allows the delivery to the reaction zone of the reactive hydrogen species (mostly atomic and ionic hydrogen) needed for precursor reduction while avoiding plasma-induced substrate damage. The RPCVD process was employed to grow copper films at temperatures in the range 150-250-degrees-C at a reactor pressure and plasma power of, respectively, 0.5-2 Torr and 75-100 W (power density of 1.5-2.2 W/cm2), with an average copper growth rate of 50-75 angstrom/min. Films thus grown were analyzed by x-ray diffraction, Rutherford backscattering, x-ray photoelectron spectroscopy, four-point resistivity probe, and scanning electron microscopy. The results of these studies showed that the films were pure (impurity levels were below the detection limits of the techniques used), uniform, continuous, and had resistivity values under 2.0-mu-OMEGA-cm.