Discharge structure of Ar/Cl2 inductively coupled plasma: A cyclic study of discharge conditions at fixed power

TL;DR

This study combines simulation, theory, and diagnostics to analyze the discharge structure of Ar/Cl2 inductively coupled plasma under fixed power, revealing classic structures, mechanisms, and stratification effects in electronegative plasma.

Contribution

It provides a comprehensive cyclic analysis of discharge conditions, integrating simulation and theory to elucidate plasma morphology and underlying mechanisms in electronegative plasma.

Findings

Identification of classic discharge structures and mechanisms

Revelation of space and species stratification effects

Analysis of non-neutralities during plasma transport

Abstract

Discharge structure refers to the morphology of different plasma quantities, such as electron temperature, reaction rate, plasma potential, mass flux, net charge and species density, which are determined by plasma transport mechanism and chemical processes. This morphology is rather difficult to refine in complex electronegative plasma for it is contained in a multiple-physics-field coupled system. Regarding this difficulty, the combination of self-consistent simulation, theory analysis and experimental diagnostic of this system is needed. In the scope of present article, the fluid simulation and analytic theory are utilized to investigate the Ar/Cl2 inductive plasma, via a cyclic tuning of discharge pressure and feedstock gas content parameters when fixing the power. Classic discharge structure (e.g., delta, parabola, flat-top, and hollow) and specific discharge mechanisms (e.g., self-coagulation, physics coagulation, de-coagulation, grouping behavior and the ambi-polar diffusion of triple species) are revealed. Besides, the two types of discharge stratification, i.e., space and species, are presented. Many non-neutralities are generated during the transport process of electronegative plasma when it gives rise to the discharge structure, which are summed and analyzed for better understanding the plasma.