Influence of gas type and input power on ion distribution in transformer coupled toroidal plasma

Transformer-coupled plasma sources are widely used in the semiconductor industry. In order to better control the plasma generated, it is urgent to understand the plasma characteristics inside transformer-coupled plasma source equipment. In this work, a two-dimensional numerical model of transformer-coupled toroidal plasma is established with considering a matching circuit. The Poisson equation and the transport equations of charged and neutral particles are calculated in a coupled way. The electron power deposition and fluid velocity are updated by calculating the specified components of Maxwell's equations and the fluid equations at specified time points. Two gas mixtures, namely Ar/NH
3
and Ar/NF
3
are studied in the simulation, and the density of Ar
⁺
in these two mixtures are compared. We also change the power of the radio frequency (RF) source coupled to the plasma and investigate the corresponding influence on the Ar
⁺
distribution. The results show that the Ar
⁺
density increases with the RF power. Since NF3 is more electronegativity than NH3, the density of Ar
⁺
in the Ar/NH
3
mixture is higher than that in the Ar/NF
3
mixture under the same condition.