Temporal evolution of the ion flux to the target in rotational RF multimagnetron plasma

Abstract

Rotational multimagnetron plasmas driven by radio-frequency power are designed by taking into account the electronic gyro-radius and Hall parameter. Temporal evolutions of the ion flux to the target have been measured at various radial positions from 0 to 50 mm at a distance of 5 mm from the target under the rotational speed of 40 rpm. The ion flux has an order of magnitude of 1023 m−2 s−1. It is found that there is hardly any time variation of the ion flux at 0 ≤ r ≤ 5 mm, whereas a strong temporal change is observed at 7.5 ≤ r ≤ 50 mm as predicted by a plasma emission image. The fluctuation of the ion flux increases from 1.3 × 1022 to 5.7 × 1023 m−2 s−1 with increasing the radial position for 0 ≤ r ≤ 32.5 mm and then has a valley of 4.7 × 1023 m−2 s−1 at r = 40 mm and has a peak of 6.4 × 1023 m−2 s−1 at r = 45 mm. The radial profile of the time-averaged ion flux is in good agreement with that of the target erosion depth.