Surface Reaction Modeling in Plasma Deposition/Etching Processing

Da Zhang and Mark J. Kushner

Department of Electrical and Computer Engineering

University of Illinois at Urbana-Champaign



During plasma deposition/etching processing of materials, complex surface reactions happen. Nowadays many researches are focusing on the surface chemical activities to make clear about the reaction mechanisms and thus to achieve better control of the manufacturing. The kinetics of the deposition/etching process is also of great importance due to its commercial meaning and its linkage to product properties like uniformity etc. Here based on most recent experimental results, we developed a surface code that takes in to consideration the reactions at the substrate surface, and calculates feedback of species/fluxes to the discharge. We can also obtain deposition/etching rate vs. surface location information by running the case.



The surface code couples with the modified HPEM code, i.e. the surface subroutines are called during HPEM code iterations. It would be functioning under the manner described below:

    1. Read in surface geometry from the reactor mesh file, making records of the direction of the interface (horizontal or vertical, right or left side facing gas), and of the distance from a certain surface cell to the starting cell (usually at the center).
    2. Read in surface reaction information from icps.dat file, which contains a list of gaseous-surface species reactions, and the probability for each reaction.
    3. Read in initial conditions about surface species/coverage from namelist file, and the initial guess for sticking coefficients of incident gaseous species are read in from the icp.dat file (a HPEM data file).
    4. Obtain & organize incident species/fluxes from HPEM calculated results for each surface cell.
    5. Surface reaction iteration. Use the results to modify surface species/coverage, and the reflecting species/fluxes to the plasma zone. Calculate deposition/etching rate as a function of surface location.
    6. Return to HPEM iteration.

Flow diagram:


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