The impact of growth parameters on the formation of InAs quantum dots on GaAs(1 0 0) by MOCVD

We have investigated InAs quantum dots (QD) formed on GaAs(1 0 0) using metal-organic chemical vapor deposition. Through a combination of room temperature photoluminescence and atomic force microscopy we have characterized the quantum dots. We have determined the effect of growth rate, deposited thickness, hydride partial pressure, and temperature on QD energy levels. The window of thickness for QD formation is very small, about 3 Å of InAs. By decreasing the growth rate used to deposit InAs, the ground state transition of the QD is shifted to lower energies. The formation of optically active InAs QD is very sensitive to temperature. Temperatures above 500°C do not form optically active QDs. The thickness window for QD formation increases slightly at 480°C. This is attributed to the thermal dependence of diffusion length. The AsH 3 partial pressure has a non-linear effect on the QD ground state energy.