Advancement in the probe diagnostics for characterization of a Capacitively Coupled RF Discharge

Capacitively coupled Radio Frequency (CCRF) discharges find diverse applications, spanning from plasma processing of semiconductors to ion thrusters crucial for satellite positioning and generating energetic charged particle beams from plasma sources in space. There are two essential parameters for the plasma processing techniques: the ion density and its energy accelerated by the sheath. Therefore, it is crucial to determine the plasma density and the electron temperature, as the ionization rate is directly proportional to the electron temperature (T_e), and the sheath potential is also coupled to T_e. For this purpose, multiple diagnostics techniques have been developed, such as the RF-compensated Langmuir probe, EEDF measurements using the 2nd harmonic detection method, and RF-compensated biased Hairpin Resonator Probe. The probe theories have been revisited and implemented according to the discharge conditions. This study explores the application of these probe diagnostics for the characterisation of a low-pressure geometrically asymmetric 13.56 MHz driven capacitively coupled plasma (CCP) cylindrical device.