Enhancing plasma uniformity by employing non-uniform magnetic field modulation in capacitively coupled plasmas

Abstract

A two-dimensional implicit electrostatic particle-in-cell model is applied for the simulation of non-uniformly magnetized capacitively coupled plasmas. In the absence of a magnetic field, the plasma density is concentrated at the center of the reactor, under the studied parameters. This leads to the formation of a radial density gradient and subsequently generates a radial electric field that causes the deflection of incident ions toward the bottom electrode. Minimizing ion deflection is imperative in order to prevent detrimental effects on plasma processing. In pursuit of this objective, a static magnetic field is applied to the capacitively coupled plasmas by installing direct current coils on the upper section of the reactor. This arrangement has been observed to considerably alter the radial distributions of plasma density and the incident angle of ion bombardment on the bottom electrode.