The effect of intermediate frequency on sheath dynamics in collisionless current driven triple frequency capacitive plasmas

• Published in: Physics of plasmas 2017-01, Vol.24 (1)
• Main Authors: Sharma, S., Mishra, S. K., Kaw, P. K., Turner, M. M.
• Format: Article
• Language: English
• Subjects: Distribution functions; Electrons; Heating; Ion energy distribution; Parameter sensitivity; Particle in cell technique; Plasma jets; Plasma physics; Plasmas (physics); Sheaths
• ISSN: 1070-664X; 1089-7674
• DOI: 10.1063/1.4973889

The Capacitively Coupled Plasma discharge featuring operation in current driven triple frequency configuration has analytically been investigated, and the outcome is verified by utilising the 1D3V particle-in-cell (PIC) simulation code. In this analysis, the role of middle frequency component of the applied signal has precisely been explored. The discharge parameters are seen to be sensitive to the ratio of the chosen middle frequency to lower and higher frequencies for fixed amplitudes of the three frequency components. On the basis of analysis and PIC simulation results, the middle frequency component is demonstrated to act as additional control over sheath potential, electron sheath heating, and ion energy distribution function (iedf) of the plasma discharge. For the electron sheath heating, effect of the middle frequency is seen to be pronounced as it approaches to the lower frequency component. On the other hand, for the iedf, the control is more sensitive as the middle frequency approaches towards the higher frequency. The PIC estimate for the electron sheath heating is found to be in reasonably good agreement with the analytical prediction based on the Kaganovich formulation.