Atomic Interfacial Structures in Fe/GaAs Films

We discuss the effect of the atomic interfacial structure on the Schottky barrier height in Fe/GaAs films. HRTEM image simulations, produced using the microscopy software JEMS, were used to predict the interfacial structure of Fe/GaAs thin films. Comparisons between experimental images, obtained using a JEOL FS2200 microscope, and the image simulations show the interfaces to contain various structures. This leads to regions with different barrier properties giving a distribution of barrier heights. This would create preferential regions for tunnelling across the film which would dominate device characteristics.