Influence of buffer layers on the In-content of GaInN layers

Abstract

In this work we have studied the influence of different buffer layers on the composition of GaInN layers grown by LP-MOVPE. We obtained the indium-content in these layers by XRD-measurements of the symmetrical reflex (0 0 2) and asymmetrical reflexes, for example (1 0 5). GaInN layers of about 100 nm thickness were grown at 750°C on different (Al,In)GaN buffer layers. We found that the In-content in GaInN changes with the buffer material up to 50%. Moreover, reciprocal space maps showed large variations of relaxation of the GaInN. For example GaInN layers grown on GaN buffer are almost fully strained. However, GaInN on AlN is largely relaxed.