Electron microscope studies of interdiffusion in molecular beam epitaxy grown GaInAs/AlInAs multilayers

The thermal interdiffusion behavior of intrinsic nominally lattice‐matched GaInAs/AlInAs heterostructures grown by molecular‐beam epitaxy, studied using electron microscopy, is reported. At temperatures as low as 700 °C, significant degrees of interdiffusion are observed. X‐ray microanalysis of the multilayers reveals that the interdiffusion takes place along a nonlinear (that is, non‐lattice‐matched) path. This behavior has previously been attributed to the pronounced differences in the elemental diffusivities of the constituent binary compounds. In addition, high‐resolution electron microscopy (HREM) was used to determine the detailed interfacial structure of the material. Such a determination is only possible under favorable and well‐defined experimental conditions. The accuracy and limitations of HREM analysis of interfacial abruptness in semiconductor interfaces are commented on.