Numerical simulations of the effects of radiofrequency cables on the single-frequency capacitively coupled plasma

Radiofrequency (RF) coaxial cables are one of the vital components for the power sources of capacitively coupled plasmas (CCPs), by which the RF power is transferred to excite the plasma. Usually, the cables can be treated as transmission lines (TLs). However, few studies of TLs in CCP power sources were conducted due to the nonlinear coupling between TLs and the plasma. In this work, we developed a numerical scheme of TLs based on the Lax-Wendroff method and realized the nonlinear bidirectional coupling among the lumped-element model, transmission line model, and electrostatic particle-in-cell model. Based on the combined model, three discharge patterns were found, including weak matching state, normal state, and over matching state. The great differences among the three patterns indicated that the TLs could change the impedance matching of the device and significantly affect the plasma properties.

Automated summary

This work developed a numerical model for transmission lines based on the Lax-Wendroff method and achieved nonlinear bidirectional coupling among the lumped-element model, transmission line model, and electrostatic particle-in-cell model. It was found that the transmission lines can change the impedance matching of the device and significantly affect the plasma properties.