AVS 57th International Symposium & Exhibition
    Thin Film Thursday Sessions
       Session TF-ThM

Paper TF-ThM5
New Parameterization of the Modified Embedded Atom Potential for Large Scale Simulations of TiN Thin Films Growth

Thursday, October 21, 2010, 9:20 am, Room Ruidoso

Session: Modeling and Analysis of Thin Films
Presenter: D.G. Sangiovanni, Linköping University, Sweden
Authors: D.G. Sangiovanni, Linköping University, Sweden
V. Chirita, Linköping University, Sweden
L. Hultman, Linköping University, Sweden
Correspondent: Click to Email
Classical Molecular Dynamics (MD) has become an indispensable tool in thin films modeling, as it allows the study of systems and phenomena reaching far beyond the inherent limitations of ab-initio and/or Density Functional Theory (DFT) methods. Generally, the range of systems to which the method can be applied has typically been limited to materials characterized by single-type bonding, such as ionic, covalent or metallic. This situation has been considerably improved in the last decade within the formalism of the Modified Embedded Atom Method (MEAM), which allows the treatment of mixed-type bonding materials, and in recent years, a number of studies have been devoted to MD simulations of important model systems such as TiN. Nevertheless, the very few MEAM parameterizations for TiN reported thus far are able to reasonably reproduce bulk, as well as some surface properties of this material. However, if meaningful MD simulations of TiN thin films growth are to be performed, a number of critical nucleation and diffusion phenomena have to be accounted for besides basic bulk/surface properties. Herein, we propose a new parameterization of the MEAM interaction potential for TiN, which in addition to correctly predicting bulk and surface properties, reproduces the experimentally observed trends in the diffusion of single species (Ti, N) and Ti-N dimers, on the most representative steps/surfaces for TiN growth, the (100) and (111) respectively. Our estimations of activation energies for diffusion and Ehrlich-Schwoebel (ES) step-edge barriers are in good agreement with previous ab-initio calculations and experimental observations. Consequently, this new MEAM parameterization has the potential to adequately account for most essential processes during the initial stages of TiN nucleation, which, as it is well known, dramatically affect the growth mode and properties of thin films in laboratory and computer experiments.