Growth of tetrahedral amorphous carbon film: Tight-binding molecular dynamics study

Abstract

Molecular dynamics simulation using tight-binding potential has been performed to examine the growth and performance of tetrahedral amorphous carbon during ion deposition. The sp3 hybrid atom content, density, and compressive stress of the tetrahedral amorphous carbon film depend on the growing conditions such as substrate temperature, ion energy, ion dose, and annealing temperature. The critical temperature for sp3 transition to sp2 decreases with ion energy (40, 80, and 120 eV). At low temperatures (<300 K) and low ion energies, the sp3 fraction increases up to 82%. At the annealing temperature less than 1200 K or with a few ions (<20) implanted into the film, its sp3 content and density have only slight changes while the compressive stress has a large reduction with the annealing temperature and the number of implanted ions. This large reduction in the compressive stress is due to a structural relaxation. © 2005 Elsevier Ltd. All rights reserved.