SURFACE-MORPHOLOGY OF METALORGANIC VAPOR-PHASE EPITAXY-GROWN INAS ANDINGAAS OBSERVED BY ATOMIC-FORCE MICROSCOPY

We have studied the surface morphology of metalorganic vapor phase epi taxy grown InAs and InGaAs by atomic force microscopy. InAs monolayer steps were observed on an annealed InAs substrate. Monolayer steps and terraces were also observed on I:he grown InAs homoepitaxial layers. Step edges are smooth and straight on the grown samples. The: growth m ode is by step flow. In the case of InGaAs lattice matched to an InP s ubstrate, steps are not as straight as those of InAs layers. This is d ue to a higher surface concentration gradient near step edges. Two-dim ensional islands were observed on the monolayer terraces at a high gro wth rate of 1.2 nm/s. (C) 1996 American Vacuum Society.