Bd. Min et al., SUPPRESSION OF OSTWALD RIPENING IN IN0.5GA0.5AS QUANTUM DOTS ON A VICINAL (100) SUBSTRATE, Physical review. B, Condensed matter, 57(19), 1998, pp. 11879-11882
A comparative study of the morphology of self-assembled In0.5Ga0.5As q
uantum dots grown by atmospheric pressure metal-organic chemical vapor
deposition on the exact (100) and 2 degrees-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, wherea
s the dots on the 2 degrees-off (100) substrate are aligned along mult
iatomic steps. As the interruption time t is increased, the density of
dots on the exact (100) substrate decreases and their average volume
progressively increases with similar to t(3/4) dependence, indicating
a regular Ostwald-ripening process. By contrast, the average volume of
dots on the 2 degrees-off (100) substrate saturates for interruption
times over 200 sec and shows obvious suppression of ripening. In parti
cular, the size of dots on the 2 degrees-off (100) substrate is limite
d within the atomic terrace width (similar to 55 nm). These results de
monstrate that the density and size of dots could be controlled by int
erruption time and substrate miscut angle. [S0163-1829(98)04416-6].