The effect of growth temperature on the structure of GaSb/GaAs quantum dots grown by MOCVD

Dot size and density are important factors that determine the physical properties of semiconductor materials based on arrays of self-assembled dots (SADs). We report the effects of growth temperature on strained GaSb three-dimensional (3D) islands on GaAs grown by metalorganic chemical vapor deposition (MOCVD). In this work we use growth temperatures of 480/spl deg/C, 500/spl deg/C, 520/spl deg/C, and 540/spl deg/C. The results show decreasing dot widths as growth temperature increases. On the other hand, the dot densities generally increase. We believe that the increase in growth temperature increases adatom diffusion length and consequently leads to more extensive dots. However, fragmentation due to elastic relaxation appears to compensate at higher temperatures. As a result the dot density increases again, while average sizes fall.