Abstract :
High resolution core level photoelectron spectroscopy PES.and scanning tunneling microscopy STM.have been used
to study the adsorption and desorption of S on and off the Ge 100.surface. The previously proposed bridge adsorption site
of S is consistent with our results at low coverage. At saturation the substrate contains several GeSx species, with xs0.5 to
4. Both photoemission and STM reveals a non-ideal surface, with a saturation coverage above one monolayer. Furthermore,
S is found to etch the substrate. The reaction products forms a disordered overlayer on top of the interface. This overlayer is
transparent in the filled state STM images
