Session S10 - Poster Session (During Extended Coffee Breaks Throughout Conference).
POSTER session, Friday afternoon, October 24
Cochise, Memorial Union
The Ge/Si(100) system has been studied intensely in the past due to the fact that is a great model for observing the mechanisms involved in the Stranaski-Krastanov growth mode, described as layer-by-layer growth followed by the formation of islands, or dots. These mechanisms, driven by a 4.2lattice mismatch, are still not fully understood. Elevated temperature scanning tunneling microscopy (ET-STM) can assist us in better understanding these mechanisms by observing the kinetics of Ge on the surface of Si(100) at the atomic level. Currently, we have an ultra high vacuum ET-STM capable of depositing Ge via digermane on Si(100) substrates held at temperatures between 350 to 650 degrees Celsius. Preliminary results have resulted in 'movies' showing the growth of the wetting layers which then lead to the formation of Ge quantum dots. From these movies we are able to monitor aspects of Ge growth such as quantum dot volume over time, revealing critical radii as a function of growth temperature.