EFFECT OF METHYL SURFACE SATURATION DURING GROWTH INTERRUPTION SEQUENCES OF METALORGANIC VAPOR-PHASE EPITAXY OF IN0.53GA0.47AS USING TRIMETHYLARSENIC

We have investigated the use of trimethylarsenic (TMAs) as an alternat ive to arsine in the metal organic vapor-phase epitaxy (MOVPE) of hete rostructures containing arsenic-based compounds on InP. We particularl y. focused this study on the growth interruption sequences (GIS) betwe en two arsenic-based materials rising TMAs. We show that a too long st abilization time under TMAs is not desirable. It produces a saturation of the surface with methyl radicals that hampers the growth of the se cond material (after the GIS). This results in a very poor surface mor phology of the sample, An important improvement of the surface morphol ogy is achieved using a long hydrogen purge after the stabilization ti me under TMAs. This allows the desorption of most of the methyl radica ls on the surface before the growth of the second layer. However, even with this hydrogen purge, the surface morphology is not perfect and p resents some defects.