Spatial structure of a radio-frequency magnetron plasma at various Ar gas pressures for hydrophobic film preparation with a fluoropolymer PFA target

Magnetic characteristics of electrons are analysed based on a simulated magnetic flux density distribution near the magnets in a radio-frequency (RF) magnetron sputtering for discussing the electron magnetization. Spatial distributions of the ion saturation current are measured with a heated Langmuir probe to avoid a deposition of a dielectric layer on the probe during RF magnetron sputtering with a fluoropolymer Perfluoroalkoxy alkanes (PFA) target at various argon gas pressures of 0.1, 0.3 and 0.5 Pa. It is found that the radial profile of the ion saturation current has a peak between the center magnet and the outer magnet near the target and then approaches a uniform profile with increasing the distance from the target for 0.1 Pa, whereas for 0.3 and 0.5 Pa it has two peaks, one at the electrode center and another one between the center magnet and the outer magnet. The first peak position is determined by the E × B drift motion. Collision effects play an important role for determining the spatial structure of the ion saturation current. • Electron magnetization in an RF magnetron plasma is discussed based on simulated magnetic field distributions. • Heated Langmuir probe measurements clarified the spatial structure of the ion flux. • Ion flux distribution has one peak in radial direction at 0.1 Pa, while it has two peaks at 0.3 and 0.5 Pa. • The first peak position is determined by the E × B drift motion. • Collision effects play an important role for determining the ion flux distribution.