skip to main content

Title: First principles-based multiparadigm, multiscale strategy for simulating complex materials processes with applications to amorphous SiC films

Progress has recently been made in developing reactive force fields to describe chemical reactions in systems too large for quantum mechanical (QM) methods. In particular, ReaxFF, a force field with parameters that are obtained solely from fitting QM reaction data, has been used to predict structures and properties of many materials. Important applications require, however, determination of the final structures produced by such complex processes as chemical vapor deposition, atomic layer deposition, and formation of ceramic films by pyrolysis of polymers. This requires the force field to properly describe the formation of other products of the process, in addition to yielding the final structure of the material. We describe a strategy for accomplishing this and present an example of its use for forming amorphous SiC films that have a wide variety of applications. Extensive reactive molecular dynamics (MD) simulations have been carried out to simulate the pyrolysis of hydridopolycarbosilane. The reaction products all agree with the experimental data. After removing the reaction products, the system is cooled down to room temperature at which it produces amorphous SiC film, for which the computed radial distribution function, x-ray diffraction pattern, and the equation of state describing the three main SiC polytypes agreemore » with the data and with the QM calculations. Extensive MD simulations have also been carried out to compute other structural properties, as well the effective diffusivities of light gases in the amorphous SiC film.« less
Authors:
 [1] ;  [2] ;  [3] ; ;  [1]
  1. Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-1211 (United States)
  2. (United States)
  3. Materials and Process Simulation Center, California Institute of Technology, Pasadena, California 91125 (United States)
Publication Date:
OSTI Identifier:
22415753
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 142; Journal Issue: 17; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CERAMICS; CHEMICAL VAPOR DEPOSITION; COMPLEXES; COMPUTERIZED SIMULATION; EQUATIONS OF STATE; FILMS; GASES; MOLECULAR DYNAMICS METHOD; POLYMERS; PYROLYSIS; QUANTUM MECHANICS; SILICON CARBIDES; SPATIAL DISTRIBUTION; TEMPERATURE RANGE 0273-0400 K; VISIBLE RADIATION; X-RAY DIFFRACTION