Measurement of the electron energy distribution function and E-H mode transition in inductively coupled plasma with various gases

A study of the E-H mode transition was performed in Ar, O2, N2, and mixture gas inductively coupled plasma (ICP) from the measurement of the electron energy distribution function (EEDF). Change of the EEDF and characteristic of the discharge on the E-H mode transition were discussed. At each E mode, the measured EEDFs had different shapes depending on the gas type and pressure, while the EEDFs evolved into Maxwellian distribution with the E-H transition due to electron-electron collisions. This study was also focused on the transition ICP power from E mode to H mode. As the ICP power increased in Ar discharge, the transition ICP power had minimum value at a particular pressure, while the transition ICP power was gradually increased with gas pressures in molecule gas discharge. The transition ICP power with gas mixing ratios was also studied in Ar/O2/N2 mixture gas discharge.