Self-consistent simulation of the impedance matching network for single frequency capacitively coupled plasma

Matching networks are of vital importance for capacitively coupled plasmas to maximize the power transferred to the plasma discharge. The nonlinear interaction between the external circuit and plasma has to be considered to design suitable matching networks. To study the effect of the matching circuit, we coupled PIC/MC model and nonlinear circuit equations based on Kirchhoff’s laws, in a fully nonlinear and self-consistent way. The single-frequency capacitively coupled discharge with ”L”-Type matching networks are simulated. Fully self-consistently results of circuit and plasma parameters are presented and then power absorbed by the plasma and efficiency are calculated. With the tune of the matching network, the efficiency can reach 28.7 %, leading to higher potential as well as higher electron density at fixed source voltage. Besides, only very small components of the third harmonics are found in the plasma voltage and current while surface charge densities have multiple harmonics on account of the strong plasma nonlinearity. Finally, the effects of matching capacitors on discharge are analyzed, results show that smaller Cm1 and Cm2 of 500 pF to 1000 pF may be a proper choice for better matching, resulting in higher voltage across the CCP, and thus higher electron density and power absorption efficiency are obtained.