Critical lateral size for stress domain formation in InAs/GaAs square nanomesas: A multimillion-atom molecular dynamics study

Abstract

Lateral size effects on the stress distribution and morphology of InAs/GaAs square nanomesas are investigated using molecular dynamics (MD) method. Two mesas with the same vertical size but different lateral sizes are simulated. For the smaller mesa, a single stress domain is observed in the InAs overlayer, whereas two stress domains are found in the larger mesa. This indicates the existence of a critical lateral size for stress domain formation in accordance with recent experimental findings. The InAs overlayer in the larger mesa is laterally constrained to the GaAs bulk lattice constant but vertically relaxed to the InAs bulk lattice constant. © 2001 American Institute of Physics.