Two-step growth of metamorphic GaAs/AlGaAs mirror on an InP substrate by MOCVD

This paper describes a high-reflectivity metamorphic undoped GaAs/Al0.98Ga0.02As distributed Bragg reflector grown on an InP substrate by metalorganic chemical vapor deposition (MOCVD). Optimal two-step growth conditions at low and high growth temperatures can provide a smooth surface morphology, leading to a high reflectivity (> 99.5%) with little optical scattering loss. We also show that a large mismatched interface does not create dislocations in the active layer at a slow cooling rate after the growth sequence. These results indicate that metamorphic GaAs/Al0.98Ga0.02As directly grown on an InP substrate by MOCVD is promising for application to InP-based vertical cavity surface-emitting laser structures.