High rate sputtering for Ni films by an rf-dc coupled magnetron sputtering system with multipolar magnetic plasma confinement

Abstract

Ni films were prepared by an rf-dc coupled magnetron sputtering with multipolar magnetic plasma confinement (MMPC) at the low pressure of 6.7×10−2 Pa and at the long distance of 120 mm, when permanent magnets were placed around a nickel target (200 mm φ, 5 mm thick) outside the chamber. When rf power and dc bias voltages were applied simultaneously to the target, the deposition rate of the Ni films significantly increased with the target dc bias voltage (VT). The highest value of the deposition rate was about 250 nm/min at VT=−820 V. The high rate sputtering for Ni films was possible at the low Ar gas pressure of 6.7×10−2 Pa. The resistivity for all the films deposited at different dc bias voltages was 7.1–8.2 μΩ cm whose value was close to the bulk value. It is shown that the sputtering system with MMPC has some advantages in comparison with conventional magnetron sputtering, such as high deposition rate, plasma discharge stability, and the preparation of high quality magnetic thin films.