We describe a technique for the quantitative measurement of composition in Al_xGa_(1−x)As heterostructures using a simple solid‐state backscattered electron detector in a scanning electron microscope. Calibration data are presented and are shown to be consistent with the Castaing [Adv. Electron. Electron Phys. 13, 317 (1960)] theory. The technique is applied to image representative Al_xGa_(1−x)As heterostructures including a graded index separate confinement heterostructure (GRINSCH) laser structure
