AVS 52nd International Symposium
    Plasma Science and Technology Thursday Sessions
       Session PS+MS-ThM

Invited Paper PS+MS-ThM1
Particle Modeling of Plasmas and Gases in Materials Processing

Thursday, November 3, 2005, 8:20 am, Room 302

Session: Process Equipment Modeling
Presenter: K. Nanbu, Tohoku University, Japan
Authors: K. Nanbu, Tohoku University, Japan
T. Furubayashi, Tohoku University, Japan
Correspondent: Click to Email
The use of low gas pressure is a recent trend in plasma-assisted materials processing. The low gas pressure means that the collision frequency between two species are insufficient to recover the equilibrium in the velocity distributions. In such a case the particle modeling of plasmas and gases has more sense. First, it is shown that the particle modeling is a solution method of the Boltzmann equation. This gives the theoretical basis of the DSMC (direct simulation Monte Carlo method) for neutral gases and the PIC/MC (particle-in-cell Monte Carlo method) for plasmas. Second, the state-of-the-art modeling is discussed by introducing the problems thus far solved. Last, the results of two newly solved problems are given to show the feasibility of the particle modeling. One is the complicated gas flows in an etching apparatus, consisting of source gases Ar, C@sub 4@F@sub 6@, and O@sub 2@, radicals CF@sub 2@ and C@sub 3@F@sub 4@, and by-products SiF@sub 4@ and CO. The second is the self-sputtering of copper target. The species in the sputtering apparatus are electrons, ions, and sputtered atoms. Here we propose a method to simulate all these species simultaneously even though the velocity difference among species is disparate. This is the first application of the particle modeling to the problem where the slow neutral species are taken into consideration together with charged particles.@footnote 1@ @FootnoteText@ @footnote 1@ K. Nanbu, IEEE Trans. Plasma Science, Vol. 28 (2000), 971-990.