In situ observation of MEE GaAs growth using scanning electron microscopy

Abstract

We have used in situ scanning electron microscopy (SEM) for real-time observation of migration enhanced epitaxy (MEE) processes. The surface morphology developed during MEE growth is either monolayer islands or monolayer holes depending on the amount of Ga supply per growth cycle. When island coverage is low, the islands disappear immediately after growth terminates, while the holes remain longer. Resulting surface roughness is much smaller than in molecular beam epitaxy even at a low substrate temperature. The present observations directly confirm enhancement of surface atom migration in MEE.