Formation of a 3~(1/2) × 3~(1/2) surface on Si/Ge(111) studied by STM and LEED

摘要

We have performed a detailed study of the formation and the atomic structure of a 3~(1/2) × 3~(1/2) surface on Si/Ge(111) using both scanning tunneling microscopy (STM) and low energy electron diffraction (LEED). Both experimental methods confirm the presence of a 3~(1/2) × 3~(1/2) periodicity but unlike the Sn/Ge(111) and the Sn/Si(111) surfaces, the Si/Ge(111) surface is not well ordered. There is no long range order on the surface and the 3~(1/2) × 3~(1/2) reconstruction is made up of double rows of silicon atoms separated by disordered areas composed of germanium atoms.