Kinetic Study of Effects of RF Pulsing in Dual Frequency Capacitively Coupled Plasma

Kinetic effects are important in low pressure capacitively coupled plasmas used for numerous plasma etch and deposition applications. In this work, dual frequency capacitively couple plasma sustained in Argon is characterized using electrostatic Particle-in-cell/Monte Carlo collision method for charged particles. Both the source (high frequency) and bias (low frequency) voltages are pulsed in the simulations. The objective of this work is to examine simultaneous pulsing of both the sources, and how pulsing design impacts targeted plasma applications where we would like to uniquely control the dynamics of plasma-surface interaction. Pulsing parameters (synchronous/staggered pulsing, pulse duty cycle and pulse frequency) are varied and temporal evolution of plasma characteristics such as plasma density, flux and energy of electrons and ions, density of excited neutrals, charge and displacement currents along with time-averaged particle distribution functions over pulsing cycle are studied. Especially, we looked at the staggered pulsing between source and bias voltages to study dynamic stabilization of plasma characteristics during offset period. Moreover, to understand complex nature of level-to-level pulsing, a comparative study is performed to study the impact of level-to-level pulsing over continuous excitation.