Investigation of Plasma Parameters During Mode Transition in Magnetic-Pole-Enhanced- Inductively Coupled Neon Plasma

Magnetic-pole-enhanced inductively coupled plasmas (MaPE-ICPs), in comparison with the conventional ICPs, operate in two modes (E and H) dependent upon the power coupling mechanisms, i.e., a low-power capacitive coupling mode (E-mode) and a comparatively high-power inductive coupling mode (H-mode). In this paper, the key plasma parameters during the E-H transition are investigated in neon MaPE-ICP for numerous applied powers (5-100 W) and gas pressures (1-100 Pa). The electron density and electron energy probability functions (EEPFs) are measured by means of a single Langmuir probe (LP). The electron temperature is evaluated by employing an LP, a Boltzmann plot (BP), and the modified BP methods. It is observed that the electron density enhances, whereas the electron temperature reduces with applied RF power and pressure of the feed gas in both the modes of the discharge. In E-mode, the measured EEPFs evolve from the bi-Maxwellian behavior to Druyvesteyn-like distributions with an increase in pressure due to the transition in electron heating mode with pressure. However, the higher electron-electron collision frequency forces the EEPFs to become Maxwellian in the H-mode of the discharge.