Comparative study of electron temperature and excitation temperature in a magnetic pole enhanced-inductively coupled argon plasma

Magnetic Pole Enhanced-Inductively Coupled Plasmas (MaPE-ICPs) in analogy to the conventional ICPs exhibit two modes of operation, depending on the power coupling mechanism, i.e., a low power mode with dominant capacitive coupling (E-mode) and a high power mode with dominant inductive coupling (H-mode). A comparative study of the electron temperature measured by a Langmuir probe ( T e LP ) and the electron excitation temperature ( T exc OES ) determined by Optical Emission Spectroscopy (OES) is reported in the two distinct modes of a MaPE-ICP operated in argon. The dependence of T e LP , T exc OES and their ratio ( T e LP / T exc OES ) on applied power (5–50 W) and gas pressure (15–60 mTorr) is explored, and the validity of T exc OES as an alternative diagnostic to T e LP is tested in the two modes of MaPE-ICP. The OES based non-invasive measurement of the plasma parameters such as electron temperature is very useful for plasma processing applications in which probe measurements are limited.