Control of Magnetic Field for Sustainment of Ion Production and Uniform Ion Flux to Substrate in Neutral Loop Discharge Plasma

摘要

We simulated electron and ion motions in a neutral loop discharge plasma under the control of the foot of the separatrix sweeping over the substrate and the neutral loop moving within a short distance from the RF antenna by a Monte Carlo method. We analyzed the distributions of ion production and ion flux to the substrate. We found that ion production is sensitive to the magnetic field gradient rather than to the electric field strength. Moreover, by superposing the flux distributions weighted by the residence time of the foot of the separatrix on the substrate, we obtained a uniform time-averaged distribution of the ion flux to the substrate in a radius range of r = 4.0 to 14.0 cm with σ/m = 0.25% (m: mean, σ: standard deviation).