Abstract
A comparative study of the morphology of self-assembled quantum dots grown by atmospheric pressure metal-organic chemical vapor deposition on the exact (100) and 2°-off (100) GaAs substrates as a function of growth interruption time (0–1200 sec) is presented. The dots are randomly distributed on the exact (100) substrate, whereas the dots on the 2°-off (100) substrate are aligned along multiatomic steps. As the interruption time is increased, the density of dots on the exact (100) substrate decreases and their average volume progressively increases with dependence, indicating a regular Ostwald-ripening process. By contrast, the average volume of dots on the 2°-off (100) substrate saturates for interruption times over 200 sec and shows obvious suppression of ripening. In particular, the size of dots on the 2°-off (100) substrate is limited within the atomic terrace width These results demonstrate that the density and size of dots could be controlled by interruption time and substrate miscut angle.
- Received 13 November 1997
DOI:https://doi.org/10.1103/PhysRevB.57.11879
©1998 American Physical Society