Methods of Improving Accuracy in InGaN MQWs Quantitative Analysis by STEM/EDS

The composition of InGaN/AlN/GaN MQWs nano structure is anlayzed by STEM/EDS. The concentration of nitrogen in GaN materials is usually lower than that of gallium for specimen thickness larger than 50 nm due to low penetration ability of N K X-rays (0.392 KeV). The concentration of indium in the InGaN quanturm wells obtained by STEM/EDS analysis is always much lower its real value. This concentration dilution in this 3 nm structure results from the effect of electron beam broadening, and can be improved to a certain level by reducing specimen thickness, C2 aperture, and dwell time, with a sacrifice in signal intensity.