Effects of a cathode fall region on deposition rate of copper atoms in Dc plasma sputtering source

Abstract

A theoretical investigation was carried out to show the effect of the length of the cathode fall region on the deposition rate of copper atoms on a substrate using dc plasma sputtering source. The effects of the discharge voltage (−1 to −3 kV) and argon gas pressure (1 × 10–2 to 5 × 10–1 mbar) on the length of the cathode fall region of the proposed plasma source were investigated. The flux energies of gas ions, neutral’s gas atoms and electrons in one dimension were calculated to determine the length of the cathode fall region, total current density and the rate of deposition of copper atoms. The results show that the length of the cathode fall region increases when low gas pressure is used at high values of the discharge voltage for the plasma source. There is also a relationship between the length of the cathode fall region and the rate of deposition of copper atoms on the substrate, where the deposition rate increased by 76% when the cathode fall length increased by 120% at the discharge voltage −3 kV and the pressure of gas 1 × 10–2 mbar.