High-rate deposition of copper thin films using newly designed high-power magnetron sputtering source

We have deposited copper (Cu) thin films on Si(100) and glass substrates in the growth temperature range between 573 and 753 K using a pulsed DC magnetron sputtering method. Based on the magnetic field simulation, we have designed and constructed a high-power (120 x 10(-4) W/m(2)) unbalanced magnetron sputtering (UBM) source for high-rate deposition. The maximum deposition rate of the newly developed sputtering source under a target power density of 115 x 10(-4) W/m(2) we have obtained is 2.8 mum/min. This is five times higher than that using the conventional sputtering method, and the sputtering yield also reached 70% due to low voltage and high-current Cu-accelerated ions. We have also adapted an ion extraction grid between the Cu target and substrate. Although the growth rate was decreased to 2 mum/min, XRD and XPS showed that highly oriented polycrystalline Cu(Ill) thin films without carbon and oxygen impurities were obtained with lowest electrical resistivity of 2.0 x 10(-2) muOmegam at a target power density of 96.7 x 10(-4) W/m(2), substrate temperature of 723 K, and working pressure of 1.3 x 10(-1) Pa. During film deposition, moreover, plasma diagnostics was also carried out in situ by optical emission spectroscopy analysis. (C) 2004 Elsevier B.V. All rights reserved.