The effect of a remote plasma generator on a direct inductively coupled plasma

The electron energy distribution functions (EEDFs) were measured in a planar inductively coupled plasmas (ICP) with a remote plasma generator (RPG) using Langmuir probes. RF power frequencies of the ICP and the RPG were 13.56 MHz and 2 MHz, respectively. While the gas pressure and the argon flow rate are varied, the plasma density is changed little with the RPG, however, the electron temperature is changed remarkably. The change in electron temperature is not monotonically decreased and the pressure condition of minimum electron temperature is moved. This phenomenon can be explained by the changes in EEDFs depending on the RPG.