Influence of the secondary electron emission on the characteristics of radio frequency plasmas

Abstract

In this paper the influence of secondary emission on the characteristics of RF plasmas has been studied. An asymmetrical dual-frequency capacitively coupled plasma reactor has been modeled with one dimensional PIC/MCC (Particle in Cell with Implemented Monte Carlo Collisions) code. The main feature of the modeling code represents the realistic model of the ion-induced secondary electron emission. Secondary emission of electrons is one of the important processes that effects the characteristics of rf plasmas. For modeling the secondary yield per ion, we have used equations proposed by Phelps and Petrovic (Plasma Sources Sci. Technol. 8 (1999) R21-R44) for differently treated metal surfaces. In the model, the energy dependence of the yields per ion for differently treated metal surfaces has been implemented. Results are compared for yields for the so called ?dirty? and ?clean? surfaces, and the spatial profiles of charged particles and ion energy distributions were observed. The simulation results indicate that the plasma characteristics are greatly affected by the ion-induced secondary emission, changing the overall parameters of dual-frequency capacitively coupled plasma reactors especially in applications as etching devices. Conclusion is that an exact model of the secondary electron emission should be included, as to ensure better agreement between simulation and experiment.