A TEM study of InGaAs/GaAs SQWs grown by MOVPE on (100) and 2° off (100) GaAs substrates

InGaAs SQWs grown on vicinal (100) GaAs substrates exhibit wide macrosteps that cause marked lateral and vertical fluctuations in composition and thick-ness that increase with increasing layer thickness and composition. Macrosteps are absent for growth on exact (100) oriented substrates. Dislocation loops in the substrate and threading dislocations, both generated by reaction between misfit dislocations, are created more easily for growth on vicinal substrates than substrates of exact orientation.