Simulation of Heteroepitaxial Growth using KMC: Lattice and Off-Lattice Approaches
Peter Smereka (Unversity of Michigan), Tim Schulze (University of Tennessee), Henry Boateng (University of Michigan)
From Atomistics to Reality: Spanning Scales in Simulations and Experiments Symposium A
Mon 9:00 - 10:30
CIT 165
Simulation of strained heteroepitaxial growth using kinetic Monte Carlo is computationally challenging due to the need to repeated update the long ranged elastic interactions. This talk will discuss various computational techniques that have been developed to efficiently simulate a weakly off-lattice model using KMC. In this setting, the energy of the system is approximated by a bond counting/ball and spring model. Our methods have proved to be sufficiently fast so that we have been able to simulate heteroepitaxial growth for physically realistic parameter regimes. These computations have provided insight into phenomena that have been only poorly understood in the past. These include quantum dot formation, alignment of quantum dots and their erosion during capping. In addition we have extended the weakly off-lattice model to a fully off-lattice formulation. Here, the energy of the system is modeled using an inter-molecular potential. Our fully off-lattice approach has the advantage of being able to capture defects such as edge dislocations, interstitials, and vacancies.