Composition Dependence of Equal Thickness Fringes in an Electron Microscope Image of GaAs/Al_xGa_1-x As Multilayer Structure

Abstract

A new method is presented for the composition analysis of GaAs/Al x Ga 1- x As multilayer structure using transmission electron microscopy. It is found that the position of equal thickness fringe observed at the edge of a cleaved chip is closely related to the composition. Change in Al composition in GaAs/Al x Ga 1- x As superstructure is observed as a shift of the equal thickness fringe. Compositional abruptness at the heterointerface and compositional fluctuation in the thin layer can be estimated in the electron microscope image.