Two-dimensional fluid simulation and Langmuir probe measurement of a planar inductively coupled oxygen plasma

A two-dimensional (2D) self-consistent axisymmetric fluid simulation of an inductively coupled discharge of electronegative oxygen plasma with a one-t urn antenna placed on the top of the dielectric roof is presented. The mode l equations include continuity equations, the Poisson equation. and an elec tron energy balance equation. For a planar inductive discharge, the electri c field component E-theta (r, z) is calculated, assuming axisymmetric geome try. Considering a deep penetration of the induced rf field, the power depo sition profile is formulated and used as the electron heating term in the e lectron energy balance equation. The 2D distributions of charged particle d ensities, electric potential, electron temperature, and ionization I are ar e calculated and compared with experiments. The effect of neutral gas press ure on plasma characteristics is investigated. As a result, for a relativel y low pressure (5 mTorr) case, the ionization rate and charged particle den sities are uniform in the radial direction, and Cor a medium pressure (20 m Torr) case, the ionization rate and the negative ion density are sharply ma ximized in the axial and radial directions. The results of the simulation a gree reasonably well with the results of the spatially averaged global mode l and experimental results.