Plasma drift in a low-pressure magnetized radio frequency discharge

Abstract

A bright strip-like structure is observed in a low-pressure capacitively coupled radio frequency discharge with a magnetic field perpendicular to the plasma flow. The structure forms for a broad set of operating conditions in different gases. Measurements indicate that the strip acts as a path for the electrons to cross the magnetic field, which makes the discharge inhomogeneous and non-symmetrical. The strip intensity is strongly reduced when switching from a capacitive to an inductive discharge. A theoretical analysis shows that the strip results from a drift of the magnetized electrons perpendicular to the magnetic and electric fields, which is intercepted by the dielectric walls of the discharge tube. In capacitive mode, the drift is mostly governed by the electric field whereas the pressure dominates in inductive mode.