Interdiffusion of GaInNAs/GaAs laser structures

The effects of annealing InGaNAs/GaAs heterostructures on diffusion at the interfaces and the resultant changes in optical and structural properties have been studied. Interdiffusion between In and Ga was found to be obvious. Inserting a thin In/sub xd/Ga/sub 1-xd/N/sub yd/As/sub 1-yd/ layer on either side of an In/sub xq/Ga/sub 1-xq/N/sub yq/As/sub 1-yd/ quantum well (QW) suppressed this interdiffusion significantly. As a consequence, blue shift of the photoluminescence signal after annealing remained small and the optical activity was significantly improved. It was also found that a small amount of N incorporated in InGaAs QWs embedded in GaAs increased In/Ga interdiffusion and that increased mechanical stresses enhanced the interdiffusion.