Electrical characterization of an inductively coupled gaseous electronics conference reference cell

Abstract

Plasma parameters and particularly the external electrical operational parameters are examined with respect to mode transition and hysteresis. The external electrical parameters such as antenna current (Ic) and antenna voltage (Vc) amplitudes are measured after the matching network and discussed for an inductively coupled argon discharge. A wide range of discharge conditions by varying applied power (up to 150 W at 13.56 MHz), gas pressure (0.7–7.5 Pa), and electrostatic coupling strength are measured for a gaseous electronics conference radio frequency reference cell. The effect on the power coupling efficiency by varying electrostatic coupling strength is studied via implementing two distinct grounded Faraday shields, in addition to the original nonshielded condition. A brief discussion on the evolution of floating potential, plasma potential, electron density, and electron energy distribution function with power and pressure is also presented mainly in context to mode transitions and hysteresis. Relatively smooth transitions in the plasma parameters and in the external electrical parameters are measured close to H to E mode transition region. Contrary to plasma parameters, however, the reverse transition from E to H mode was found to be abrupt in external parameters. The plasma parameters are measured using a commercial Langmuir probe, whereas the antenna currents and voltages are measured using a homebuilt Rogowski coil and capacitor divider, respectively.