Hydrogen-induced domain-wall structure on Si(113)

In-situ high resolution electron diffraction (SPA-LEED) and scanning tunneling microscopy (STM) measurements during the chemical vapor deposition growth from disilane (Si2H6) on Si(113) show a variety of different surface reconstructions, depending on the equilibrium hydrogen coverage on the surface adjustable by substrate temperature. At high H coverage, a regularly formed missing row structure with light domain walls is observed. At low H coverage, STM images reveal large uncovered areas between several hydrogen-terminated rows, changing the light domain wall structure into a heavy domain wall structure. The domain wall formation depends only on the equilibrium H coverage on the surface and is fully reversible with desorption of the hydrogen. The relation between the observed surface structures and thermal desorption of H is shown in a phase diagram. The activation energy for the transitions was found to be 2.1 eV and agrees well with the desorption energy for atomic hydrogen determined by growth oscillations.