We have applied high-resolution chemical imaging in a transmission electron microscope to study compositional variations across an InGaAs/InAlAs double quantum well structure in the (100) orientation. The structures of interest are grown on an InP support and consist of two 40 Å layers of InGaAs separated by 20 Å of InAlAs. For this (InGa)x(InAl)1-xAs system, we have obtained compositional information with an accuracy of about 20% and a maximum spatial resolution of 1/4 unit cell. The results clearly show compositional irregularities on a monatomic scale.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)