Investigation of nonlinear dynamics in capacitively coupled radio frequency discharges
Schabnam Naggary, Abd Elfattah Elgendy, Thomas Mussenbrock, Ralf Peter Brinkmann
DPG Frühjahrstagung 2013, Jena, Germany, 25 February - 01 March
Capacitively coupled radio frequency plasmas (RF-CCPs) are widely used in material processing. Considering of the complicated analysis of the dynamic behavior of RF-CCPs, global models provide a simple understanding of these dynamics with relatively little effort. Based on the matrix sheath model approach and description of the nonlinear charge-voltage characteristics of the sheath by a quadratic approximation, the global model yields a reasonable approximation of the RF current through the discharge. However, a more accurate description of the dynamics of RF-CCPs needed by the most plasma technologies can be obtained by applying a more exact sheath model realized by a cubic charge-voltage characteristic which gives a better agreement with experimental results. This work shows that a small variation in the cubic charge-voltage characteristic compared to the quadratic approximation leads to considerably modification of the RF current which in turn has a significant influence on the power dissipation in the bulk.