EVOLUTION OF SURFACE-TOPOGRAPHY DURING METALORGANIC VAPOR-PHASE EPITAXY OF INP INGAAS/INP QUANTUM-WELL HETEROSTRUCTURES/

The evolution of surface topography during epitaxial growth of lattice matched InP/InGaAs/InP on (100) InP substrate is observed using in si tu elastic light scattering supported by ex situ atomic force microsco py. A topographically smooth growth transition from InP to InGaAs is o bserved. However, the InP-on-InGaAs interface exhibits three-dimension al nucleation followed by planarization and two-dimensional epitaxy. T he three-dimensional phase is a result of the high surface energy of I nP relative to InGaAs. A growth pause after the InGaAs QW increases th e transient roughness of the InP surface and increases the thickness o f InP required for planarization. (C) 1994 American Institute of Physi cs.