Incorporating Electronegative Feedback Mechanisms in a Global Plasma Circuit Model for Pulsed Power Delivery*

Pulsed inductively coupled plasmas (ICP) have been of interest in the semiconductor industry given their ability to reduce substrate damage and modulate key parameters such as electron density n_e, electron temperature T_e, and plasma potential V_p. For an electropositive plasma, in the power ON-Cycle of a pulse, these discharges are typically characterized by a sharp increase in T_e, and n_e, as well as a corresponding decrease or increase in the reflection coefficient (Γ), depending on the match settings_­. In previous work, a Matlab based Global Plasma Circuit Model (GPCM) has successfully been employed at characterizing these transients for argon. This work presents computational results from GPCM with an SF₆ Plasma and benchmarks them with hairpin and photodiode taken on the Inductively Coupled Argon Oxygen System (ICAROS). Modifications to the equivalent transformer model are also incorporated, such that electronegative effects such as electron attachment instabilities (EAI’s) can be accounted for. Finally, the role that match effects has on inducing these EAI’s are also explored, as it has been observed that modulating the topology of the match can change the behavior of instabilities.