Simple modelling of the E-H mode transition and hysteresis in low pressure argon ICP discharges for direct comparison with experiments

The E-H mode transition and hysteresis in low pressure argon inductively coupled discharges are investigated using a global model and a transformer model. The total absorbed power by the plasma and the coil current are calculated as a function of the electron density at fixed RF injected power rather than fixed RF coil current as previously shown in the literature. We found that the transition corresponds to a difference of the absorbed power efficiency between E and H mode. The calculation results show the existence of an inaccessible region between E and H mode as well as a threshold coil current and a minimum absorbed power for the H mode. Hysteresis is well reproduced by this simple calculation and can be directly compared with experimental data.