Modeling ALD Surface Reaction and Process Dynamics using Absolute Reaction Rate Theory

Authors

  • Curtisha D. Travis,

    1. Department of Chemical and Biomolecular Engineering, Institute for Systems Research, University of Maryland, College Park, MD 20742 (USA)
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  • Raymond A. Adomaitis

    Corresponding author
    1. Department of Chemical and Biomolecular Engineering, Institute for Systems Research, University of Maryland, College Park, MD 20742 (USA)
    • Department of Chemical and Biomolecular Engineering, Institute for Systems Research, University of Maryland, College Park, MD 20742 (USA)
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  • The authors acknowledge the support of the NASA Goddard Space Flight Center, the National Science Foundation through grant CBET-0828410, and the Gates Millennium Scholars Program.

Abstract

A physically based model of atomic layer deposition (ALD) surface reaction dynamics is developed and applied to alumina ALD with water and trimethylaluminum precursors. The time-dependent growth surface composition is modeled by computing the equilibrium precursor adduct surface concentrations during each half-reaction and the rate constants of the ligand exchange reactions using transition state theory. To describe the continuous cyclic operation of the deposition reaction system, a numerical procedure to discretize limit-cycle solutions is developed and used to distinguish saturating growth per cycle (GPC) from non-saturating (gpc) conditions. The transition between the two regimes is studied as a function of precursor partial pressure, exposure time, and temperature.

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