OBSERVATION OF SULFUR-TERMINATED GAAS(001)-(2X6) RECONSTRUCTION BY SCANNING-TUNNELING-MICROSCOPY

Scanning tunneling microscopy (STM) images of smooth, in situ prepared , sulfur-terminated (S-terminated) GaAs(001) surface reconstruction ar e presented. It is found that (2X6) surface reconstruction is dominant on the S-terminated GaAs(001) surface. This (2X6) reconstruction, of which the cell contains five S-S adatom dimers, is determined by both STM and reflection high-energy electron diffraction. The atomic model, which is consistent with both STM images and electron counting heuris tics, is also shown. Moreover, this (2X6) reconstruction is also obser ved in the case of an (NH4)(2)S-x-treated surface. (C) 1994 American I nstitute of Physics.