15-20 June 2014
Laurentian University / Université Laurentienne
America/Toronto timezone
Welcome to the 2014 CAP Congress! / Bienvenue au congrès de l'ACP 2014!

Defect complex evolution in semiconductors: long-range elastic interactions matter

19 Jun 2014, 09:30
15m
C-304 (Laurentian University / Université Laurentienne)

C-304

Laurentian University / Université Laurentienne

Sudbury, Ontario
Oral (Non-Student) / orale (non-étudiant) Condensed Matter and Materials Physics / Physique de la matière condensée et matériaux (DCMMP-DPMCM) (R1-3) Ion Beam Analysis and Modification - DCMMP / Analyse et modification de faisceaux d'ions - DPMCM

Speaker

François Schiettekatte (Université de Montréal)

Description

Current models of implantation damage annealing consider either point defect diffusion or damage complexes that anneal by processes internal to the complexes. However, neither of these models explains the broad shape or the heat release observed by nanocalorimetry. Here, we compare the heat release of 10 or 80 keV Si ions implanted at low-fluence (0.02-0.1 Si/nm2) in monocrystalline Si at 110 K or 300 K, to a newly proposed atomistic simulation method that runs over time scales reaching seconds. [1] The kinetic Activation-Relaxation Technique (k-ART), an off-lattice kinetic Monte-Carlo method with on-the-fly catalogue construction. This method takes fully into account all elastic effects both for energy minima and barriers. Here, k-ART is applied to a 27 000-atom cell of Stillinger-Weber silicon self-implanted with a single ion at a 3-keV. The simulation results reveal a logarithmic time dependence of defect annealing and closely reproduce the heat-release experiments. It is found that the process occurs in a process where the system needs to unlock metastable states, a process that requires crossing ever-higher barriers with time. These unlocking steps do not generally decrease the potential energy; they only allow relaxation to eventually take place. Interestingly, relaxation does not affect significantly the energy landscape, the system still seeing evolving through a similar, uniform distribution of barrier. The picture that emerges is that self-implantation or keV-recoil-induced damage in c-Si consists of a collection of relatively simple structures that, rather than only relaxing by interacting with the crystal surrounding them, overcome reconfiguration barriers in order to interact with each other and undergo relaxation, resulting in a logarithmic time-dependent evolution. Given that long-range elastic effects are a general feature found in most materials, we estimate that these conclusions apply at least to many covalently bond crystals, but probably also to many other materials. [1] L.K. Béland, Y. Anahory, D. Smeets, M. Guihard, P. Brommer, J.-F. Joly, J.-C. Pothier, L.J. Lewis, N. Mousseau, F. Schiettekatte, Phys. Rev. Lett. 111 (2013) 105502

Primary authors

François Schiettekatte (Université de Montréal) Laurent K. Béland (Université de Montréal) Matthieu Guihard (Université de Montréal) Normand Mousseau (Université de Montréal) Yonathan Anahory (Université de Montréal)

Presentation Materials

There are no materials yet.