Nonlocal electron dynamics in low pressure miniature inductively coupled radio frequency discharges

Abstract The electron dynamics and plasma characteristics in a miniature inductively coupled radio frequency plasma operated in argon are comprehensively examined utilizing a two-dimensional implicit particle-in-cell/Monte Carlo model. It is revealed that the energetic electrons originating from the skin layer close to the radio frequency coil can be transported to the bottom of the reactor collisionlessly, forming a second current layer with enhanced local current density. Both chamber height and radius critically influence the second current layer and even the phase difference between the local electric field and current, which is strongly related to power deposition. The sheath at boundary surfaces is found to play an important role in the nonlocal electron behaviors of energetic electrons. Application of a negative DC bias to the bottom electrode induces an expanded sheath, amplifying the second current layer.