Variation in hysteresis phenomenon and electron density in Ar/He plasma

We observed changes in electron energy distribution and hysteresis phenomenon with varying Ar/He ratio in inductively coupled plasma. The results were obtained by measuring antenna current and electron energy probability function. Decrease of the hysteresis area is observed at 220 mTorr by increasing the helium, 'non-Ramsauer' gas, to the argon, 'Ramsauer' gas. Because the electron energy distribution changes from 'Druyvesteyn' to 'Maxwellian' in E-mode of the Ar/He plasma as the helium ratio increases. In helium plasma, there is no change in electron energy distribution which is 'Maxwellian' distribution. So as the helium ratio increases, it reduces the change in the electron energy distribution between mode transitions in ICP. Furthermore, in the case of pure helium plasma, we found that the electron density is higher than pure argon plasma in E-mode. Because the collisional energy loss of argon plasma in E-mode is larger than helium plasma, and the plasma absorption power is less than helium.