AVS 58th Annual International Symposium and Exhibition
    Tribology Focus Topic Thursday Sessions
       Session TR+AS+SS-ThM

Paper TR+AS+SS-ThM3
Atomistic Simulations of Nanoindentation and Nanoscratching of SiO2/Si and HfO2/Si Systems using COMB Potentials

Thursday, November 3, 2011, 8:40 am, Room 111

Session: Atomic-scale Characterization of Tribological Interfaces
Presenter: Tzu-Ray Shan, University of Florida
Authors: T.-R. Shan, University of Florida
X. Sun, University of Florida
S.R. Phillpot, University of Florida
S.B. Sinnott, University of Florida
Correspondent: Click to Email
Oxides such as SiO2, Al2O3 and HfO2, are typically used together with Si in many high-performance electronic devices, including metal-oxide-semiconductor (MOS) devices/junctions and micro- and nano- electromechanical systems (MEMS/NEMS). The lack of precise control over mechanical properties can lead to the degradation of these materials. It is therefore critical to understand the nanometer-scale mechanical properties of materials or complex systems being considered for use in electronic devices. Nanoindentation and nanoscratching are important methods for investigating the mechanical behavior of small volumes of materials, such as thin film systems. Here, classical molecular dynamics simulations are used to examine the responses to nanoindentation and nanoscratching of thin films of SiO2 and HfO2 on silicon substrates. The goal is to determine the influence of thin film types and the structure of thin film and substrate interface on the responses. Because these systems consist of heterogeneous interface with significant changes in bonding as one crosses from one side of the interface to the other, the empirical charge optimized many-body (COMB) potential as implemented in large-scale atomic/molecular massively parallel simulator (LAMMPS) program is used to model the structural evolution, mechanical response and charge transfer in these systems in response to a nanometer-scale spherical indenter. Aspects of the SiO2/Si and HfO2/Si interfaces during nanoindentation and nanoscratching, including the mechanisms by which fracture and plasticity occurs, will also be addressed. We gratefully acknowledge the support of the National Science Foundation through grant numbers DMR-0426870 and DMR-1005779).