AVS 60th International Symposium and Exhibition
    Plasma Science and Technology Tuesday Sessions
       Session PS-TuP

Paper PS-TuP19
Multi-Peaked and Stepped Electron Velocity Distributions in RF-DC Discharge with Secondary Emission

Tuesday, October 29, 2013, 6:00 pm, Room Hall B

Session: Plasma Science and Technology Poster Session
Presenter: A. Khrabrov, Princeton Plasma Physics Laboratory
Authors: A. Khrabrov, Princeton Plasma Physics Laboratory
I.D. Kaganovich, Princeton Plasma Physics Laboratory
P. Ventzek, Tokyo Electron America
L. Chen, Tokyo Electron America
Correspondent: Click to Email
Hybrid RF-DC capacitively coupled discharges find important and growing applications in industrial processes. In such discharges, secondary electrons emitted from the electrodes undergo a complicated motion defined by acceleration in, and bouncing between a steady and an oscillating sheath. For the secondary electrons that return to, and impinge upon the RF electrode, the arrival energy is a non-monotonic function of the driving voltage phase at which they were emitted. This basic property leads to a velocity distribution with multiple peaks [1,2]. This effect may explain the multiple peaks in the electron energy distribution function measured in RF-DC system at RF electrode [2,3]. The energy dependence upon the phase of arrival can also be discontinuous (as the number of bounces between the sheaths changes by plus or minus one), which corresponds to a distribution containing steps. Further, the velocity distribution of secondary electrons is sensitive to variations in the bouncing time and may form additional peaks if a small high-frequency ripple is present in the RF sheath voltage [2]. We have found such features in numerical test-particle simulations of the discharge, and analyzed the observed structure of the electron distributions. [1] D. Israel, K.-U. Riemann, and L.D. Tsendin, J. Appl. Phys. 99, 093303 (2006). [2] K.E. Orlov and A.S. Smirnov, Plasma Sources Sci. Technol. 10, 541(2001). [3] L. Xu, L. Chen, M. Funk, A. Ranjan, M. Hummel, R. Bravenec, R. Sundararajan, D. J. Economou, and V. M. Donnelly, Appl. Phys. Lett. 93, 261502 (2008).