In-N and N-N correlation in InxGa1-xAs1-yNy/GaAs quasi-lattice-matched quantum wells: A cross-sectional scanning tunneling microscopy study

The probability of finding In-N and N-N closely spaced pairs in InxGa1-xAs1-yNy /GaAs quasi-latticematched quantum wells (x=0.13, y=0.045) has been measured by cross-sectional scanning tunneling microscopy. The average number of In-N bonds is higher than expected for a random distribution in both as-grown and annealed samples, but lower than that predicted by current theoretical calculations. Our measurements show no N outdiffusion and little change in the spatial distribution of In atoms as a result of annealing. However, a remarkable decrease in the number of N-N nearest neighbors and associated localized states is observed in annealed quantum wells.