Structural Investigations of (GaIn)(NAs)/GaAs Multi-Quantum-Wells by Transmission Electron Microscopy

Abstract

ABSTRACTThe structure of compressively strained (GaIn)(NAs)/GaAs multi-quantum wells (MQWs) grown by MOVPE is investigated using TEM. The quaternary, metastable material exhibits a high structural perfection if a N concentration of 4% is not exceeded. Phase separation or clustering effects are not observed, and the In is dispersed homogeneously throughout the quantum wells. The interface roughness of the quantum wells to the GaAs barriers is in the order of several monolayers. Increasing the N content to above 4.5% results in a deterioration of the structure and of the homogeneity of the wells