Lieberman's radio-frequency (RF) sheath theory is extended to dual-frequency capacitively coupled plasmas. The extended RF sheath theory describes the nonlinear motion of the sheath, for example, the very high frequency (VHF) component of plasma potential varies during the low frequency (LF) cycle and shrinks at the phase such that the lower electrode potential becomes closer to the plasma potential. The theory also describes the plasma potential having a variety of frequency components due to the interaction between VHF and LF. Then the plasma potential and the sheath thickness described in the extended RF sheath theory are incorporated into the Particle-in-Cell, Monte-Carlo-Collision (PIC-MCC) sheath model. The plasma potential, the sheath thickness, and the energy distribution functions of electrons and ions impinging on the biased electrode obtained using the PIC-MCC sheath model correlate well with the results from the one-dimensional PIC-MCC plasma model.

No abstract

A simple model for ion-atom collision with charge exchange is proposed to realize a computationally efficient particle simulation of plasmas. The model is a combination of isotropic scattering and charge switching, both occurring with the same probability. When an ion-atom collision cross section is chosen to be nearly twice as large as an atom-atom collision cross section, the measured ion drift velocities and transverse diffusion coefficients for Ar+ in Ar, He+ in He, Ne+ in Ne, and Kr+ in Kr can be reproduced with reasonable accuracy using the proposed model.

The drift velocities of C(60)(+) in He, Ne, Ar, and Kr were found to be estimated with high accuracy using the drag coefficient of a solid body in free molecule flow. That is, massive C(60)(+) behaves in gases as if it were a large classical body.

No abstract