Bulavenko S. Investigation of bismuth and hydrogen interaction with Si(111) and Si(100) surfaces by scanning tunneling microscopy

The thesis is dedicated to study of bismuth and hydrogen interaction with Si(111) та Si(100) surfaces with atomic resolution using scanning tunneling micriscopy. The detailed scheme of phase changes of the Bi/Si(111)7ґ7 interface is constructed and structure of each phase is investigated with atomic resolution. A new method of scanning tunneling microscopy with Bi/W tips is developed for investigation of inaccessible corner hole atoms of Si(111)7ґ7 reconstruction. An initial stage of atomic hydrogen adsorption and its rearrangement on the surface after heating in-cluding its adsorption in the corner holes is studied. Despite the theoretical predic-tions the atoms in the corner holes are found to be twice less active than the adatoms and rest atoms. The coadsorption of bismuth and hydrogen on the Si(111)7ґ7 surface is studied. The existence of bismuth dimers in A-position on the Si(100)2ґ1 surface at an initial Bi adosorption stage at room temperature is first revealed. The moution of A-, B-dimers and their mutual transformation are studied. The existence of a new, antiphase, type of bismuth nanowires on the Si(100)2ґ1 surface is found and nature of defects in the nanowires is studied.