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Plasma Chemistry

  • Francis F. Chen
  • Jane P. Chang

Abstract

To characterize plasma-surface interactions, we first reviewed elementary reactions, gas phase kinetics, and surface kinetics. Plasma processing shares a relatively common set of steps, by which the surface reaction proceeds. Ion bombardment can alter the kinetics of one or more of the steps, creating an enhancement of the etching or deposition rate; this effect is thought to be the primary cause of anisotropy in the surface topographical change. A reasonable set of steps for plasma etching that can be used to understand the etching mechanisms are as follows (Figs. 1 and 2):
  1. 1.

    Creation of the reactive species within the plasma phase by electron-neutral collisions and subsequent chemical reactions: e- + CF4 → CF3 + F + e-

     
  2. 2.

    Transport of the reactive species from the plasma to the substrate.

     
  3. 3.

    Adsorption of the reactive species on the surface (either physisorption or chemisorption, Fig. 3).

     
  4. 4.

    Dissociation of the reactant, formation of chemical bonds to the surface, and/or diffusion into the substrate with subsequent formation of the desorbing species: F* + SiFx → SiFx+1

     
  5. 5.

    Desorption of the product species: SiF4(s) → SiF4(g)

     
  6. 6.

    Transport of the product species into the plasma.

     
  7. 7.

    Simultaneous re-deposition of etching products.

     

Keywords

Reactive Species Plasma Processing Product Species Plasma Etching Plasma Surface 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Copyright information

© Springer Science+Business Media New York 2003

Authors and Affiliations

  • Francis F. Chen
    • 1
  • Jane P. Chang
    • 2
  1. 1.Electrical Engineering DepartmentUniversity of CaliforniaLos AngelesUSA
  2. 2.Chemical Engineering DepartmentUniversity of CaliforniaLos AngelesUSA

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