Electron density reduction in magnetized capacitively coupled plasmas induced by magnetic damping of the plasma series resonance

The effects of a homogeneous transversal magnetic field on the plasma density and electron dynamics in low pressure capacitively coupled plasmas (CCP) are studied by Particle-in-Cell/Monte Carlo collision (PIC/MCC) simulations. The plasma density increases monotonously as a function of the magnetic field at low frequencies due to the enhanced magnetic confinement of electrons. In contrast with this, a strong initial decrease is observed at higher frequencies (60 MHz) and low magnetic fields, which is caused by a magnetic damping of the self-excited Plasma Series Resonance (PSR) oscillations of the RF current and the attenuation of the corresponding Non-Linear Electron Resonance Heating (NERH). By further enhancing the magnetic field, the plasma density increases due to magnetically induced electric field reversals during sheath collapse and an enhanced interaction time of electrons with the expanding sheath edge.