Structures of Al/Si(100) surfaces as determined by scanning tunneling microscopy

The structures of Al/Si(100) surfaces with coverages below 0.5 monolayer have been determined using scanning tunneling microscopy (STM). Through careful STM measurements, Al dimers are atomically resolved, where the Al dimer bond is intuitively demonstrated to be parallel to the Si dimer bond. The atomic arrangements at the ends of Al dimer rows have been discussed on the basis of the interpretation of dual-bias STM images. Two possible structures at the end of an Al dimer row are a single atom termination and a dimer termination, depending on whether the Al dimer row ends at a surface defect, respectively. (C) 1996 American Institute of Physics.