Determination Of The Nitrogen Distribution In Inganas/Gaas Quantum Wells By Transmission Electron Microscopy

We report on measurements of the nitrogen-concentration profile in an InGaNAs heterostructure by high-resolution transmission electron microscopy. Two samples grown by gas-source molecular-beam epitaxy on GaAs(001) substrates were investigated which contain InGaAs and InGaNAs wells with the same thickness and In concentration. The indium concentration was determined by high-resolution x-ray diffractometry. Indium-concentration profiles were obtained with the composition evaluation by lattice fringe analysis (CELFA) technique from the sample with the InGaAs wells exploiting the chemical sensitivity of the diffracted (002) beam. Nitrogen-concentration profiles were measured in the InGaNAs wells by comparison of the CELFA results observed in the samples with and without nitrogen. (C) 2004 American Institute of Physics.