Inductively Coupled Plasmas**

Electronegative inductively coupled plasmas (ICPs) sustained in halogen gases are used in the microelectronics industry for etching, and passivation. Pulsing is a primary control strategy to optimize conditions.  We report on time dependent measurements of electric and magnetic field, plasma current, and power deposition in pulsed ICPs sustained in tens of mTorr Ar/O₂ mixtures with the oxygen being a surrogate electronegative gas.  A 3D probe drive system measures changing magnetic fields throughout the plasma volume.  Alternatively an RF compensated Langmuir probe is used to measure electron and positive ion densities and electric potential. Probe inferred densities are calibrated against a microwave interferometer. Negative ion density is inferred from spectroscopic measurements, as well from combined laser photodetachment and Langmuir probe measurements. Results are reported for varying ratios of argon to oxygen concentrations. Comparisons are made to modeling results.