Effect of dissipated power due to antenna resistive heating on E- to H-mode transition in inductively coupled oxygen plasma

The problem of the effective power input into plasma is investigated for the inductively coupled RF oxygen discharge operated at 13.56 MHz. The power significantly deviates especially at the E- to H-mode transition. In order to
enlighten this phenomenon the U–I characteristics of the discharge are recorded. With these data, we have recalculated the power deposited into plasma and determined the effective power losses due to the resistive antenna heating. The E–H mode transition is investigated in the pressure range from 10 to 200 Pa. With an increase of the working gas pressure, the threshold for the E–H transition moves towards the higher powers. The transition exhibits a hysteresis for the pressures higher than 10 Pa. When the dissipated power due to the antenna resistive heating is taken into account, the characteristic hysteresis profile skews towards lower power as compared to the case of taking generator power as a relevant parameter. This means that the E-mode is strongly affected by the way the power is obtained, while for the H-mode the generator power can be considered as a relatively good external parameter.