Composition analysis method of superstructure using equal thickness fringe.

A new method is proposed for the composition analysis of GaAs/Alx Ga1-x As superstructure using the equal thickness fringe in the transmission electron microscope image. The position of the equal thickness fringe observed at the edge of a cleaved chip shifts depending on the Al composition. The compositional dependence on the fringe shift can be explained by the dynamical electron diffraction theory. The compositional abruptness at the heterointerface and the compositional fluctuation in the thin layer can be successfully evaluated with a high spatial resolution of 0.4nm [Jpn. J. Appl. Phys. 26, 770 (1987) ] .