Fabry-Pérot transmission resonances in tunneling microscopy

We have used the tunneling microscope to observe stacking-fault contrast in conductance and topographic images of the Si(111)-7×{}7 surface as a function of applied gap bias. This contrast is found to be a strong function of the bias, with the maximal contrast occurring near energies where standing-wave formation, between the surface and a buried interface, is predicted in a one-dimensional resonant-tunneling theory. The agreement between experiment and theory indicates that this technique is useful for probing details of buried interfaces formed by surface reconstruction and in heteroepitaxial growth.