Rotational cross-shaped magnetized radio-frequency sputtering plasma source for uniform circular target utilization

A rotational cross-shaped magnetized radio-frequency (RF) sputtering plasma source was developed for uniform circular target utilization. The cross-shaped magnetized RF plasma was attained by inducing a linear E × Br drift motion using a cruciform arrangement of neodymium magnets, where E and Br are the electric field perpendicular and magnetic field parallel to the target, respectively. A two-dimensional magnetic field simulation clarified that the electrons are strongly magnetized by the Hall parameter at a magnitude 20 times that of the ions. Strong cross-shaped plasma discharges are observed. The temporal evolutions of the ion saturation current were measured by a Langmuir probe at various radial positions, and the time-averaged ion saturation current was found to decrease from the center to the outer area of the target. The target utilization percentage was found to increase from 73.6% to 86.3% when Fe pole pieces were incorporated on the cruciform arrangement of neodymium magnets.