AVS 53rd International Symposium
    Plasma Science and Technology Wednesday Sessions
       Session PS1-WeA

Paper PS1-WeA5
Modeling of Seasoning of Reactors: Effects of Ion Energy Distributions to Chamber Walls*

Wednesday, November 15, 2006, 3:20 pm, Room 2009

Session: Plasma-Wall Interactions and Plasma Sources
Presenter: M.J. Kushner, Iowa State University
Authors: A. Agarwal, University of Illinois at Urbana-Champaign
M.J. Kushner, Iowa State University
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Wafer to wafer process reproducibility during plasma etching often depends on the conditioning of the walls of the reactor. Deposition of passivation on chamber walls can change the reactive sticking coefficients for radicals, thereby changing the composition of the radical and ion flux to the substrate. Ion bombardment of the walls may affect the passivation coverage or production of etch influencing species through activation of sites or sputtering. As such the spatial distribution of ion energies on the walls and their evolution as the chamber seasons are important. These seasoning processes may occur during a single etching sequence or recipe due to there being incomplete initial seasoning or there being a change in radical fluxes to the walls. In this talk, the seasoning of plasma etching reactors will be discussed using results from a computational investigation. The Surface Chemistry Module and Sputter Module of the Hybrid Plasma Equipment Model were modified to obtain the ion energy distributions to all surfaces inside the reactor and to use them to calculate energy dependent surface reaction rates. Sputtered, energetic products from passivated side walls, and their transport to the wafer, were also accounted for using the same methodology as in magnetron sputtering. Results will be discussed for the seasoning of ICP reactors using Ar/Cl@sub 2@ gas mixtures; and CCP reactors using Ar/C@sub 4@F@sub 8@ mixtures. The consequences on reactive fluxes (magnitude and energy) to the substrate due to both wall sputtering and changes in reactive sticking coefficients will be presented. @FootnoteText@ *Work supported by Semiconductor Research Corp. and the National Science Foundation.