Self-assembled InGaAs dots grown on GaP (0 0 1) substrate by low-pressure organometallic vapor phase epitaxy

We have investigated surface morphology of InGaAs on GaP (0 0 1) substrate grown by low-pressure organometallic vapor phase epitaxy. By atomic force microscope and cross-sectional transmission electron microscopy observations, it was found that the morphology depended strongly on trimethylindium flow rate ratio (xTMIn) to the total flow rate of group-III sources. In the low xTMIn region, InGaAs was grown in layer-by-layer mode. In the high xTMIn region, on the other hand, dot formation occurred. In this study, we confirmed that Stranski–Krastanow growth mode took place in the sample grown at xTMIn=0.5.