We examined mechanisms underlying Si nanocrystal formation in Si-rich SiO2 using a combination of quantum mechanical and Monte Carlo (MC) simulations. We find that this process is mainly driven by suboxide penalty arising from incomplete O coordination, with a minor contribution of strain, and it is primarily controlled by O diffusion rather than excess Si diffusion and agglomeration. The overall behavior of Si cluster growth from our MC simulations based on these fundamental findings agrees well with experiments.
Bibliographical noteFunding Information:
The authors greatly acknowledge the National Science Foundation (CAREER-CTS-0449373 and ECS-0304026) and the Welch Foundation (F-1535) for their financial support. They would also like to acknowledge the Texas Advanced Computing Center for use of their computing resources.