Atomically Resolved Electron Reflectivity at a Metal/Semiconductor Interface

An atomically flat interface is achieved between face-centered cubic Al and diamond lattice Ge via molecular beam epitaxy (MBE). Based on the measurements of scanning tunneling microscopy (STM), an atomically resolved lateral periodic change of the electron reflectivity at the Al/Ge interface is demonstrated. The relative variation of electron reflectivity is up to ≈22% in a lateral 2 nm. It is speculated that the change of reflectivity results from the local electronic states at the Al/Ge interface. This phenomenon provides an atomically non-destructive method for detecting the buried interfacial states in hetero-structures by STM.