Effect of methyl surface saturation during growth interruption sequences of metalorganic vapor-phase epitaxy of In0.53Ga0.47As using trimethylarsenic

Abstract We have investigated the use of trimethylarsenic (TMAs) as an alternative to arsine in the metal organic vapor-phase epitaxy (MOVPE) of heterostructures containing arsenic-based compounds on InP. We particularly focused this study on the growth interruption sequences (GIS) between two arsenic-based materials using TMAs. We show that a too long stabilization time under TMAs is not desirable. It produces a saturation of the surface with methyl radicals that hampers the growth of the second material (after the GIS). This results in a very poor surface morphology of the sample. An important improvement of the surface morphology is achieved using a long hydrogen purge after the stabilization time under TMAs. This allows the desorption of most of the methyl radicals on the surface before the growth of the second layer. However, even with this hydrogen purge, the surface morphology is not perfect and presents some defects.