Charge separation in an electron cyclotron resonance plasma

Abstract

Separation of an electron cyclotron resonance (ECR) plasma flux into an ion flux and an electron flux during plasma extraction has been investigated. The phenomenon is explained by the difference between ion current distribution and electron current distribution in the ECR plasma. When magnetic force lines cross the direction of the electron flux at a larger angle, the charged particle flux separation is enhanced. Also, evaluation of the flux diffusion equation for a magnetoplasma indicates that the diffusion coefficient of the electron flux across the force lines is much smaller than that of the ion flux. The ion flux diffuses isotropically compared to the electron flux confined by the magnetic field, resulting in charged particle flux separation. The potential distribution within a wafer exposed to the ECR plasma was evaluated by the flat band voltage (Vfb) shifts in metal–nitride–oxide semiconductor capacitors. The separation of the charged particle flux causes a nonuniform potential distribution within the wafer.