SURFACE-STRUCTURE OF SI(112)

The Si(112) surface has been studied with low-energy electron diffraction (LEED) and scanning tunneling microscopy (STM). A (1 x 2) surface reconstruction was observed with LEED, and both this reconstruction and a longer period, pseudo-ordered domain structure have been imaged with STM. The shape of the domains is determined by the anisotropy of the (1 x 2) nucleation. The Si(112) surface is somewhat less reactive to acetylene than low-index surfaces of silicon, and atomic hydrogen has only a limited effect on the (1 x 2) reconstruction. Deposition of a small amount of aluminum induces a (6 x 1) reconstruction of the surface.